Methods for selecting protease resistant polypeptides

ABSTRACT

The disclosure relates to a method for selecting, isolating and/or recovering a peptide or polypeptide from a library or a repertoire of peptides and polypeptides (e.g., a display system) that is resistant to degradation by a protease such as a protease found in the serum. Generally, the method comprises providing a library or repertoire of peptides or polypeptides, incubating the library or repertoire with a protease under conditions suitable for protease activity, and selecting, isolating and/or recovering a peptide or polypeptide that is resistant to degradation by the protease and has a desired biological activity. The selected peptides and polypeptides have utility as therapeutics, e.g., for treating disease in humans.

This application is a continuation of Ser. No. 13/131,640, filed May 27,2011, which is a 371 of International Application No. PCT/EP2009/066395,filed Dec. 4, 2009, which claims the benefit of U.S. ProvisionalApplication No. 61/120,135, filed Dec. 5, 2008, which is incorporatedherein by reference.

BACKGROUND OF THE DISCLOSURE

Polypeptides and peptides have become increasingly important agents in avariety of applications, including industrial applications and use asmedical, therapeutic and diagnostic agents. However, many therapeuticpeptides, polypeptides and proteins are particularly susceptible todegradation in vivo by naturally occurring proteases. Moreover, incertain physiological states, such as inflammatory states (e.g., COPD)and cancer, the amount of proteases present in a tissue, organ or animal(e.g., in the lung, in or adjacent to a tumor) can increase. Thisincrease in proteases can result in accelerated degradation andinactivation of endogenous proteins and of therapeutic peptides,polypeptides and proteins that are administered to treat disease.Accordingly, some agents that have potential for in vivo use (e.g., usein treating, diagnosing or preventing disease in mammals such as humans)have only limited efficacy because they are rapidly degraded andinactivated by proteases.

Protease resistant polypeptides provide several advantages. For example,protease resistant polypeptides remain active in vivo longer thanprotease sensitive agents and, accordingly, remain functional for aperiod of time that is sufficient to produce biological effects. A needexists for improved methods to select polypeptides that are resistant toprotease degradation and also have desirable biological activity.

Glucagon-like peptide (GLP)-1 is an incretin hormone with potentglucose-dependent insulinotropic and glucagonostatic actions, trophiceffects on the pancreatic β cells, and inhibitory effects ongastrointestinal secretion and motility, which combine to lower plasmaglucose and reduce glycemic excursions. GLP-1 is an agonist of the GLP-1receptor. Furthermore, via its ability to enhance satiety, GLP-1 reducesfood intake, thereby limiting weight gain, and may even cause weightloss. Taken together, these actions give GLP-1 a unique profile,considered highly desirable for an antidiabetic agent, particularlysince the glucose dependency of its antihyperglycemic effects shouldminimize any risk of severe hypoglycemia. However, itspharmacokinetic/pharmacodynamic profile is such that native GLP-1 is nottherapeutically useful. Thus, while GLP-1 is most effective whenadministered continuously, single subcutaneous injections haveshort-lasting effects. GLP-1 is highly susceptible to enzymaticdegradation in vivo, and cleavage by dipeptidyl peptidase IV (DPP-IV) isprobably the most relevant, since this occurs rapidly and generates anoninsulinotropic metabolite. Strategies for harnessing GLP-1'stherapeutic potential, based on an understanding of factors influencingits metabolic stability and pharmacokinetic/pharmacodynamic profile,have therefore been the focus of intense research.

Extensive work has been done to attempt to inhibit the peptidase or tomodify GLP-1 in such a way that its degradation is slowed down whilestill maintaining biological activity. WO05/027978 discloses GLP-1derivatives having a protracted profile of action (and incorporatedherein by reference as examples of GLP-1 derivatives and analogues thatcan be used in the present disclosure). WO 02/46227 disclosesheterologous fusion proteins comprising a polypeptide (for example,albumin) fused to GLP-1 or analogues (the disclosure of these analoguesis incorporated herein by reference as examples of GLP-1 analogues thatcan be used in the present disclosure). WO05/003296, WO03/060071,WO03/059934 disclose amino fusion protein wherein GLP-1 has fused withalbumin to attempt to increase the half-life of the hormone.

However, despite these efforts a long lasting active GLP-1 has not beenproduced.

SUMMARY OF THE DISCLOSURE

The disclosure relates to methods for selecting protease resistantpeptides or polypeptides and methods for selecting peptides orpolypeptides that bind a target ligand with high affinity. Thedisclosure further relates to a method of producing a repertoire ofprotease resistant peptides or polypeptides.

In one aspect, the invention is a method for selecting a proteaseresistant peptide or polypeptide. The method comprises providing arepertoire of peptides or polypeptides, incubating the repertoire and aprotease under conditions suitable for protease activity, and recoveringa peptide or polypeptide that has a desired biological activity, wherebya protease resistant peptide or polypeptide is selected.

In one embodiment, the repertoire of peptides or polypeptides isexpressed in a display system and the protease is a protease which isexpressed in the display system or expression host. For example, in oneembodiment, the repertoire of peptides or polypeptides is expressed inbacterial cells and the protease is a protease endogenous to a bacteria.Suitably, the conditions for repertoire expression maximize expressionand activity of the endogenous protease, such as bacterial protease.Protease expression and activity is maximized, for example, byincreasing the time and/or temperature for protein expression of therepertoire in bacteria. For example the incubation time may be from 1hour to overnight (e.g., from 12 up to 24 hours) or longer (e.g. from 24up to 48 hours, or longer). In one embodiment, temperature may be from30 to 37 degrees C. or more. In addition, protease expression may beenhanced by using different bacterial strains and/or modification ofmedia ingredients. Density of the bacterial culture may also be varied.In another embodiment, the display system may be modified e.g. bygenetic modification to enhance protease expression.

In one embodiment, the repertoire is provided as a bacteriophage displaysystem wherein the bacteriophage repertoire is expressed and/oramplified in E. Coli bacterial cells, such as E. Coli TB1 cells, TC1cells or cells from E. Coli strain HB2151. Accordingly, in thisembodiment, the bacterial protease is a protease expressed endogenouslyin E. coli cells. In one embodiment, the bacterial protease may be aprotease which is expressed in the bacterial periplasm. In oneembodiment, protease expression may be during phage production,secretion or in the bacterial supernatant.

Thus, in one embodiment of the disclosure, there is provided a methodcomprising the steps of taking a bacteriophage library; expressing saidlibrary in bacteria under conditions suitable for bacterial proteaseactivity; incubating said expressed library with a target ligand wherebya protease resistant target binding peptide is selected. Optionally,said incubation with a target ligand includes the presence of a furtherprotease.

In another embodiment, the display system is a yeast display system suchas Pichia and the protease is an endogenous protease which is expressedin yeast cells.

In one embodiment, the method in accordance with the disclosure furthercomprises combining the repertoire and a further protease underconditions suitable for said further protease activity, and recovering apeptide or polypeptide that has a desired biological activity, whereby aprotease resistant peptide or polypeptide is selected. In oneembodiment, the protease is combined with the repertoire in solution(ie, the protease is not immobilized on a support). Suitably the furtherprotease is found in one or more of serum, sputum, mucus (e.g., gastricmucus, nasal mucus, bronchial mucus), bronchoalveolar lavage, lunghomogenate, lung extract, pancreatic extract, gastric fluid, saliva ortears.

In another aspect, there is provided a method for selecting a proteaseresistant peptide or polypeptide. The method comprises providing arepertoire of peptides or polypeptides, incubating the repertoire and afirst protease under conditions suitable for protease activity andfurther comprising combining the repertoire with a second protease underconditions suitable for protease activity and recovering a peptide orpolypeptide that has a desired biological activity, whereby a proteaseresistant peptide or polypeptide is selected. In one embodiment of thisaspect, the first protease is a protease endogenous to the repertoiredisplay system and the second protease is selected from a protease foundin serum, sputum, mucus (e.g., gastric mucus, nasal mucus, bronchialmucus), bronchoalveolar lavage, lung homogenate, lung extract,pancreatic extract, gastric fluid, saliva or tears. It will beappreciated, however, that the “first” and “second” protease steps canbe carried out in any order. In addition, it will be appreciated thatmultiple repeats of any such steps may be encompassed within the methodof the disclosure.

In one embodiment of any aspect of the disclosure, said conditions forsaid further or second protease activity are (i) about 10 μg/ml to about3 mg/ml protease, (ii) about 20° C. to about 40° C. and (iii) for atleast about 30 minutes. In one embodiment, these stringent conditionsenable the selection of peptides or polypeptides with high affinityand/or improved Tm. In such case, the peptides and polypeptides maydisplay high affinity in monomeric form.

In one embodiment, in the methods of the disclosure in accordance withany aspect, for said conditions suitable for protease activity about 10to about 100 μg/ml protease is used. For said conditions suitable forprotease activity a temperature of about 30 to about 37° C. (eg, atabout 37° C. or about room temperature) may be used. In one embodiment,the repertoire and protease may be combined for at least about one hour(eg, about 1 hour, about two hours, overnight e.g. 18 to 24 hours). Inthe methods of the disclosure, the repertoire and the protease are inone embodiment incubated for a period of at least about 30 minutes. Inone embodiment, the protease is used at about 100 μg/ml, and thecombined repertoire and protease are incubated at about 37° C. for atleast about hour.

In one embodiment of any aspect of the disclosure, the ratio (on amole/mole basis) of protease, eg trypsin, to polypeptide or variabledomain is 8,000 to 80,000 protease:variable domain. In one embodimentthe ratio (on a weight/weight, eg microgram/microgram basis) of protease(eg, trypsin) to polypeptide or variable domain is 16,000 to 160,000protease:variable domain. In one embodiment, the protease is used at aconcentration of at least 100 or 1000 micrograms/ml protease.

Any desired protease can be used in a method in accordance with anyaspect of the disclosure, such as one or more of the following, serineprotease, cysteine protease, aspartate proteases, thiol proteases,matrix metalloprotease, carboxypeptidase (e.g., carboxypeptidase A,carboxypeptidase B), trypsin, chymotrypsin, pepsin, papain, elastase,leucozyme, pancreatin, thrombin, plasmin, cathepsins (e.g., cathepsinG), proteinase (e.g., proteinase 1, proteinase 2, proteinase 3),thermolysin, chymosin, enteropeptidase, caspase (e.g., caspase 1,caspase 2, caspase 4, caspase 5, caspase 9, caspase 12, caspase 13),calpain, ficain, clostripain, actinidain, bromelain, separase anddipeptidyl peptidase IV (DPP-IV). In particular embodiments, theprotease is trypsin, elastase or leucozyme. The protease can also beprovided by a biological extract, biological homogenate or biologicalpreparation, eg whole cells in vitro. If desired, the method furthercomprises adding a protease inhibitor to the combination of therepertoire and the protease after incubation is complete.

In one embodiment of the any of methods of the disclosure, theprotease(s) is in solution when combined with the repertoire.

In one embodiment of any aspect of the disclosure, the desiredbiological activity is binding activity, eg to a ligand, eg a targetligand or a generic ligand.

In some embodiments, a peptide or polypeptide that has a desiredbiological activity is recovered based on a binding activity. Forexample, the peptide or polypeptide can be recovered based on binding ageneric ligand, such as protein A, protein G or protein L. The bindingactivity can also be specific binding to a target ligand. Exemplarytarget ligands include ApoE, Apo-SAA, BDNF, Cardiotrophin-1, CEA, CD40,CD40 Ligand, CD56, CD38, CD138, EGF, EGF receptor, ENA-78, Eotaxin,Eotaxin-2, Exodus-2, FAPα, FGF-acidic, FGF-basic, fibroblast growthfactor-10, FLT3 ligand, Fractalkine (CX3C), GDNF, G-CSF, GM-CSF, GF-β1,human serum albumin, insulin, IFN-γ, IGF-I, IGF-II, IL-1α, IL-1β, IL-1receptor, IL-1 receptor type 1, IL-2, IL-3, IL-4, IL-5, IL-6, IL-7, IL-8(72 a.a.), IL-8 (77 a.a.), IL-9, IL-10, IL-11, IL-12, IL-13, IL-15,IL-16, IL-17, IL-18 (IGIF), Inhibin α, Inhibin β, IP-10, keratinocytegrowth factor-2 (KGF-2), KGF, Leptin, LIF, Lymphotactin, Mullerianinhibitory substance, monocyte colony inhibitory factor, monocyteattractant protein, M-CSF, MDC (67 a.a.), MDC (69 a.a.), MCP-1 (MCAF),MCP-2, MCP-3, MCP-4, MDC (67 a.a.), MDC (69 a.a.), MIG, MIP-1α, MIP-1β,MIP-3α, MIP-3β, MIP-4, myeloid progenitor inhibitor factor-1 (MPIF-1),NAP-2, Neurturin, Nerve growth factor, β-NGF, NT-3, NT-4, Oncostatin M,PDGF-AA, PDGF-AB, PDGF-BB, PF-4, RANTES, SDF1α, SDF1β, SCF, SCGF, stemcell factor (SCF), TARC, TGF-α, TGF-β, TGF-β2, TGF-β3, tumour necrosisfactor (TNF), TNF-α, TNF-β, TNF receptor I, TNF receptor II, TNIL-1,TPO, VEGF, VEGF A, VEGF B, VEGF C, VEGF D, VEGF receptor 1, VEGFreceptor 2, VEGF receptor 3, GCP-2, GRO/MGSA, GRO-β, GRO-γ, HCC1, 1-309,HER 1, HER 2, HER 3, HER 4, serum albumin, vWF, amyloid proteins (e.g.,amyloid alpha), MMP12, PDK1, IgE, IL-13Rα1, IL-13Rα2, IL-15, IL-15R,IL-16, IL-17R, IL-17, IL-18, IL-18R, IL-23 IL-23R, IL-25, CD2, CD4,CD11a, CD23, CD25, CD27, CD28, CD30, CD40, CD40L, CD56, CD138, ALK5,EGFR, FcER1, TGFb, CCL2, CCL18, CEA, CR8, CTGF, CXCL12 (SDF-1), chymase,FGF, Furin, Endothelin-1, Eotaxins (e.g., Eotaxin, Eotaxin-2,Eotaxin-3), GM-CSF, ICAM-1, ICOS, IgE, IFNa, I-309, integrins,L-selectin, MIF, MIP4, MDC, MCP-1, MMPs, neutrophil elastase,osteopontin, OX-40, PARC, PD-1, RANTES, SCF, SDF-1, siglec8, TARC, TGFb,Thrombin, Tim-1, TNF, TRANCE, Tryptase, VEGF, VLA-4, VCAM, α4β7, CCR2,CCR3, CCR4, CCR5, CCR7, CCR8, alphavbeta6, alphavbeta8, cMET, CD8, vWF,amyloid proteins (e.g., amyloid alpha), MMP12, PDK1, and IgE. In anotherembodiment, the target ligand is GLP-1 receptor, or portions thereof.For example, in the method in accordance with any aspect of thedisclosure, the ligand may be GLP-1 receptor extracellular domain.

In particular embodiments of any aspect of the disclosure, the peptideor polypeptide is recovered by panning.

In one embodiment of any of the methods of the disclosure, therepertoire is exposed to a ligand (target ligand; generic ligand) whenin the presence of the protease and one or more members of therepertoire are selected based on binding to the ligand.

In some embodiments of any methods of the disclosure, the repertoirecomprises a display system. For example, the display system can bebacteriophage display, ribosome display, emulsion compartmentalizationand display, yeast display, puromycin display, bacterial display,display on plasmid, or covalent display. Preferred display systems linkcoding function of a nucleic acid and functional characteristics of thepeptide or polypeptide encoded by the nucleic acid. In particularembodiments, the display system comprises replicable genetic packages.

In some embodiments of any methods of the disclosure, the display systemcomprises bacteriophage display. For example, the bacteriophage can befd, M13, lambda, MS2 or T7. In particular embodiments, the bacteriophagedisplay system is multivalent. In some embodiments, the peptide orpolypeptide is displayed as a pIII fusion protein.

In one embodiment of any methods of the disclosure, the repertoire ofpeptides or polypeptides (eg, variable domains) is displayed onbacteriophage, for example at a phage library size of 10⁶ to 10¹³, eg10⁸ to 10¹² replicative units (infective virions). In one embodiment,the repertoire is displayed on bacteriophage when incubated with thesecond or further protease.

In other embodiments of any aspect of the disclosure, the method furthercomprises amplifying the nucleic acid encoding a peptide or polypeptidethat has a desired biological activity. In particular embodiments, thenucleic acid is amplified by phage amplification, cell growth orpolymerase chain reaction.

In one embodiment of any aspect of the disclosure, the repertoire ofpeptides or polypeptides is displayed on bacteriophage which areamplified and expressed in bacterial cells such as E. Coli. In thisembodiment, the repertoire of peptides or polypeptides are exposed tobacterial protease when expressed in bacterial cells.

In some embodiments, the repertoire is a repertoire of immunoglobulinsingle variable domains. In particular embodiments, the immunoglobulinsingle variable domain is a heavy chain variable domain. In moreparticular embodiments, the heavy chain variable domain is a human heavychain variable domain. In other embodiments, the immunoglobulin singlevariable domain is a light chain variable domain. In particularembodiments, the light chain variable domain is a human light chainvariable domain.

In another aspect, the disclosure is a method for selecting a peptide orpolypeptide that binds a target ligand with high affinity from arepertoire of peptides or polypeptides. The method comprises providing arepertoire of peptides or polypeptides, combining the repertoire and aprotease under conditions suitable for protease activity, and recoveringa peptide or polypeptide that binds the target ligand.

As per the above methods of the disclosure, where the desired biologicalactivity is binding activity, the ligand that is bound (target ligand;generic ligand) is not the same as the protease(s).

In another aspect, the disclosure is a method of producing a repertoireof protease resistant peptides or polypeptides. The method comprisesproviding a repertoire of peptides or polypeptides, combining therepertoire of peptides or polypeptides and a protease under suitableconditions for protease activity, and recovering a plurality of peptidesor polypeptides that have a desired biological activity, whereby arepertoire of protease resistant peptides or polypeptides is produced.

In some embodiments, a plurality of peptides or polypeptides that have adesired biological activity is recovered based on a binding activity.For example, a plurality of peptides or polypeptides can be recoveredbased on binding a generic ligand, such as protein A, protein G orprotein L.

In another aspect, the disclosure is a method for selecting a proteaseresistant polypeptide comprising an immunoglobulin single variabledomain (dAb) that binds a target ligand from a repertoire. In oneembodiment, the method comprises providing a phage display systemcomprising a repertoire of polypeptides that comprise an immunoglobulinsingle variable domain, combining the phage display system and aprotease selected from the group consisting of elastase, leucozyme andtrypsin, under conditions suitable for protease activity, and recoveringa phage that displays a polypeptide comprising an immunoglobulin singlevariable domain that binds the target ligand. Suitably, in oneembodiment of this aspect, the method further comprises incubation underconditions for expression of an endogenous protease. For example, anendogenous protease is a protease which is expressed by the displaysystem.

In some embodiments, the protease is used at 100 μg/ml, and the combinedphage display system and protease are incubated at about 37° C.overnight.

In some embodiments, the phage that displays a polypeptide comprising animmunoglobulin single variable domain that binds the target ligand isrecovered by binding to said target. In other embodiments, the phagethat displays a polypeptide comprising an immunoglobulin single variabledomain that binds the target ligand is recovered by panning.

The disclosure also relates to an isolated protease resistant peptide orpolypeptide selectable or selected by the methods described herein. In aparticular embodiment, the disclosure relates to GLP-1 receptor agonistssuch as GLP-1 peptides as described herein. Suitable GLP-1 peptides andGLP-1 peptide derivatives are set out in the Examples and in FIG. 1.Other suitable peptides include GLP-1 homologues or derivatives such asexendin and its homologues and derivatives. Further suitable derivativesinclude dipeptidyl peptidase IV resistant derivatives of GLP-1. Onepreferred peptide is identified by amino acid sequence DMS7148 (sequence6 in FIG. 1). Another preferred peptide is identified by amino acidsequence DMS7161 (sequence 11 in FIG. 1). Suitably these GLP-1 peptidesare fused to an ALBUDAB™ sequence. In another embodiment, the disclosurerelates to an isolated protease (e.g., trypsin, elastase, leucozyme)resistant immunoglobulin single variable domain (e.g., human antibodyheavy chain variable domain, human antibody light chain variable domain)selectable or selected by the methods described herein.

Advantageously, peptides or polypeptides in accordance with theinvention may display improved properties in terms of expression in lowcost hosts without proteolysis during expression, thus making them moresuitable for industrial scale production.

The disclosure also relates to an isolated or recombinant nucleic acidthat encodes a protease resistant peptide or polypeptide (e.g.,trypsin-, elastase-, or leucozyme-resistant immunoglobulin singlevariable domain) selectable or selected by the methods described herein,and to vectors (e.g., expression vectors) and host cells that comprisethe nucleic acids.

The disclosure also relates to a method for making a protease resistantpeptide or polypeptide (e.g., trypsin-, elastase-, orleucozyme-resistant immunoglobulin single variable domain) selectable orselected by the methods described herein, comprising maintaining a hostcell that contains a recombinant nucleic acid encoding the proteaseresistant peptide or polypeptide under conditions suitable forexpression, whereby a protease resistant peptide or polypeptide isproduced.

Thus, in the context of any aspect of the present disclosure, theprotease may be a protease endogenous to a display system such as abacterial protease or is found in one or more of serum, sputum, mucus(e.g., gastric mucus, nasal mucus, bronchial mucus), bronchoalveolarlavage, lung homogenate, lung extract, pancreatic extract, gastricfluid, saliva or tears. In one embodiment, the protease is one found inthe eye and/or tears. As discussed herein, the selected proteaseresistant peptides or polypeptides have utility in therapy, prophylaxisand diagnosis of disease or conditions in mammals, eg, humans. Inparticular, the peptides and polypeptides have utility as the basis ofdrugs that are likely to encounter proteases when administered to apatient, such as a human.

For example, when administered to the GI tract (eg, orally,sublingually, rectally administered), in which case the peptide orpolypeptide may be subjected to protease in one or more of the upper GItract, lower GI tract, mouth, stomach, small intestine and largeintestine. One embodiment, therefore, provides for a protease resistantpeptide or polypeptide to be administered orally, sublingually orrectally to the GI tract of a patient to treat and/or prevent a diseaseor condition in the patient.

For example, in one embodiment the disclosure relates to oraladministration of a TNF alpha antagonist peptide or polypeptide selectedor selectable by the method of the disclosure, for the treatment and/orprevention of a TNF alpha-mediated condition or disease such asarthritis (eg, rheumatoid arthritis), IBD, psoriasis or Crohn's disease.In this embodiment, the antagonist may be an anti-TNFR1 immunoglobulinsingle variable domain (dAb). In another example, the peptide orpolypeptide is likely to encounter protease when administered (eg, byinhalation or intranasally) to pulmonary tissue (eg, the lung orairways). One embodiment, therefore, provides for a protease resistantpeptide or polypeptide to be administered by inhalation or intranasallyto pulmonary tissue of a patient to treat and/or prevent a disease orcondition in the patient. Such condition may be asthma (eg, allergicasthma), COPD, influenza or any other pulmonary disease or conditiondisclosed in WO2006038027, incorporated herein by reference.

In another example, the peptide or polypeptide is likely to encounterproteases in serum when administered parenterally, for example throughinjection e.g. subcutaneously. One embodiment, therefore, provides for aprotease resistant peptide or polypeptide to be administered byinjection and to treat and/or prevent a disease or condition in thepatient. Such condition may be diabetes. In one embodiment, thedisclosure provides for parenteral administration of a glucagonlike-peptide 1 receptor agonist such as GLP-1 or its homologues andderivates, such as exendin or derivatives thereof, selected orselectable by the method of the disclosure for the treatment and/orprevention of diabetes or diabetes-related disorders.

The peptides and polypeptides according to the disclosure may displayimproved or relatively high melting temperatures (Tm), providingenhanced stability. High affinity target binding may also be a featureof the peptides and polypeptides. These features, combined with proteaseresistance, makes the peptides and polypeptides amenable to use as drugsin mammals, such as humans, where proteases are likely to beencountered, eg for GI tract, pulmonary tissue or parenteraladministration.

In another example, the peptide or polypeptide (eg, variable domain orantagonist) is likely to encounter protease when administered (eg, byintraocular injection or as eye drops) to an eye of a patient. Oneembodiment, therefore, provides for ocular administration of theprotease resistant peptide, polypeptide, immunoglobulin single variabledomain, agonist or antagonist to a patient (eg, to a human) by to treatand/or prevent a disease or condition (eg, a disease or condition of theeye) in the patient. Administration could be topical administration tothe eye, in the form of eye drops or by injection into the eye, eg intothe vitreous humour.

In one embodiment, the disclosure provides a pulmonary formulation fordelivery to the lung, wherein the formulation comprise an agonist,antagonist, peptide, polypeptide or variable domain of the disclosurewith a particle size range of less than 5 microns, for example less than4.5, 4, 3.5 or 3 microns (eg, when in Britton-Robinson buffer, eg at apH of 6.5 to 8.0, eg at a pH of 7 to 7.5, eg at pH7 or at pH7.5).

In one embodiment, the formulations and compositions of the disclosureare provided at a pH from 6.5 to 8.0, for example 7 to 7.5, for example7, for example 7.5.

Peptide or polypeptides (eg, variable domains) according to any aspectof the disclosure may have a Tm of at least 50° C., or at least 55° C.,or at least 60° C., or at least 65° C., or at least 70° C. An agonist,antagonist, use, method, composition, device or formulation of thedisclosure may comprise such a peptide or polypeptide.

In one aspect of the disclosure, the peptides, polypeptides, variabledomains, agonists, antagonists, compositions or formulations of thedisclosure are substantially stable after incubation (at a concentrationof polypeptide or variable domain of 1 mg/ml) at 37 to 50° C. for 14days in Britton-Robinson buffer. In one embodiment, at least 65, 70, 75,80, 85, 86, 87, 88, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99% of thepeptide, polypeptide, agonists, antagonist or variable domain remainsunaggregated after such incubation at 37 degrees C. In one embodiment,at least 65, 70, 75, 80, 85, 86, 87, 88, 90, 91, 92, 93, 94, 95, 96, 97,98, 99% of the peptide, polypeptide or variable domain remains monomericafter such incubation at 37 degrees C. In one embodiment, at least 5,10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 86, 87,88, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99% of the peptide, polypeptide,agonist, antagonist or variable domain remains unaggregated after suchincubation at 50 degrees C. In one embodiment, at least 5, 10, 15, 20,25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 86, 87, 88, 90, 91,92, 93, 94, 95, 96, 97, 98, 99% of the peptide, polypeptide or variabledomain remains monomeric after such incubation at 50 degrees C. In oneembodiment, no aggregation of the peptide, polypeptides, variabledomains, agonists, antagonists is seen after any one of suchincubations. In one embodiment, the pI of the peptide, polypeptide orvariable domain remains unchanged or substantially unchanged afterincubation at 37 degrees C. at a concentration of polypeptide orvariable domain of 1 mg/ml in Britton-Robinson buffer.

In one aspect of the disclosure, the peptide, polypeptides, variabledomains, agonists, antagonists, compositions or formulations of thedisclosure are substantially stable after incubation (at a concentrationof polypeptide or variable domain of 100 mg/ml) at 4° C. for 7 days inBritton-Robinson buffer at a pH of 7 to 7.5 (eg, at pH7 or pH7.5). Inone embodiment, at least 95, 95.5, 96, 96.5, 97, 97.5, 98, 98.5, 99 or99.5% of the peptide, polypeptide, agonist, antagonist or variabledomain remains unaggregated after such incubation. In one embodiment, atleast 95, 95.5, 96, 96.5, 97, 97.5, 98, 98.5, 99 or 99.5% of thepeptide, polypeptide or variable domain remains monomeric after suchincubation. In one embodiment, no aggregation of the peptide,polypeptides, variable domains, agonists, antagonists is seen after anyone of such incubations.

In one aspect of the disclosure, the peptide, polypeptides, variabledomains, agonists, antagonists, compositions or formulations of thedisclosure are substantially stable after nebulisation (at aconcentration of polypeptide or variable domain of 40 mg/ml) eg, at roomtemperature, 20 degrees C. or 37° C., for 1 hour, eg in a jet nebuliser,eg a Pari LC+ cup. In one embodiment, at least 65, 70, 75, 80, 85, 86,87, 88, 90, 91, 92, 93, 94, 95, 95.5, 96, 96.5, 97, 97.5, 98, 98.5, 99or 99.5% of the peptide, polypeptide, agonist, antagonist or variabledomain remains unaggregated after such nebulisation. In one embodiment,at least 65, 70, 75, 80, 85, 86, 87, 88, 90, 91, 92, 93, 94, 95, 95.5,96, 96.5, 97, 97.5, 98, 98.5, 99 or 99.5% of the peptide, polypeptide orvariable domain remains monomeric after such nebulisation. In oneembodiment, no aggregation of the peptide, polypeptides, variabledomains, agonists, antagonists is seen after any one of suchnebulisation.

The peptide or polypeptide can be isolated and/or recombinant.

Suitably in one embodiment of any aspect of the disclosure, the proteaseresistant peptide or polypeptide is selected from a repertoire ofpeptides or polypeptides.

The disclosure also relates to a protease resistant peptide orpolypeptide (e.g., trypsin-, elastase-, or leucozyme-resistantimmunoglobulin single variable domain) selectable or selected by themethods described herein for use in medicine (e.g., for therapy ordiagnosis). The disclosure also relates to use of a protease resistantpeptide or polypeptide (e.g., trypsin-, elastase-, orleucozyme-resistant immunoglobulin single variable domain) selectable orselected by the methods described herein for the manufacture of amedicament for treating disease. The disclosure also relates to a methodof treating a disease, comprising administering to a subject in needthereof, an effective amount of a protease resistant peptide orpolypeptide (e.g., trypsin-, elastase-, or leucozyme-resistantimmunoglobulin single variable domain) selectable or selected by themethods described herein.

In one embodiment of any aspect of the disclosure, the method furthercomprises combining a second protease with the repertoire of proteaseresistant peptides or polypeptides under conditions suitable foractivity of the second protease; and

recovering at least one peptide or polypeptide that has a desiredbiological activity, whereby at least one peptide or polypeptide that isresistant to the second protease is selected. The first and secondproteases are different. The second protease may be as defined above. Inone embodiment, the first or second protease is endogenous to therepertoire display system.

The disclosure further provides an isolated GLP-1 receptor agonistcomprising a peptide or polypeptide, that is resistant to one or moreprotease mentioned above, when incubated with the protease under theconditions suitable for a method of the disclosure, eg a condition of(i) about 10 μg/ml to about 3 mg/ml protease, (ii) about 20° C. to about40° C. and (iii) for at least about 30 minutes. (eg, under the conditionof 100 μg/ml or protease at 37° C. for at least one hour), foradministration to a patient for treating and/or preventing diabetes. Theagonist may be used for administration by injection.

In one embodiment of the methods of the disclosure, the selected peptideor polypeptide is further assessed for resistance to a second proteaseor to the first protease but under a set of conditions that differ fromthose used in the selection method. The second protease is differentfrom the first protease, but otherwise can be any protease describedabove. In one embodiment, more than one protease resistant peptide orpolypeptide is selected in the methods of the disclosure, followed by afurther step of determining which of these peptide(s) or polypeptide(s)shows resistance to a second protease or to the first protease but undera set of conditions that differ from those used in the selection method.The second protease is different from the first protease, but otherwisecan be any protease described above. In this way, one or more peptidesor polypeptides is arrived at which is resistant to more than oneprotease. In one embodiment, the first or second protease is a proteasethat is endogenously expressed in the repertoire display system.

In one embodiment of the methods of the disclosure, a protease resistantmonomeric peptide or polypeptide (eg, an immunoglobulin single variabledomain monomer) is selected.

The medicaments, agonists and antagonists of the disclosure may comprisean antibody constant region (eg, an Fc) fused to said peptide orpolypeptide.

In one embodiment, the disclosure provides the use of protease resistantpeptide or polypeptide in the manufacture of a medicament foradministration to a mammal for providing a medicament with an improvedPK. Improved PK may be an improved AUC (area under the curve) and/or animproved half-life. In one embodiment, the protease resistant peptide orpolypeptide is selected or selectable by a method of the disclosure. Inone embodiment, the peptide or polypeptide is an immunoglobulin singlevariable domain. The medicament may comprise an antibody constant regionfused to said peptide or polypeptide, eg an antibody Fc.

The disclosure provides a medicament comprising a protease resistantpeptide or polypeptide for administration to a mammal (eg, a human) forproviding a medicament with an improved PK in the mammal. In oneembodiment, the protease resistant peptide or polypeptide is selected orselectable by a method of the present disclosure. In one embodiment, thepeptide or polypeptide is an immunoglobulin single variable domain. Themedicament may comprise an antibody constant region (eg, an Fc) fused tosaid peptide or polypeptide.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1: Shows sequences of GLP-1-ALBUDAB™ fusion variants 1-10.

FIG. 2: Shows a gel of GLP-1-ALBUDAB™ fusion variants 6-10.

FIG. 3: Shows a gel of GLP-1-ALBUDAB™ fusion variants 6-10(concentrated).

FIG. 4: Shows a gel of GLP-1-ALBUDAB™ fusion variant 11.

FIG. 5: Shows MS results of GLP-1-ALBUDAB™ fusion variants 6-11.

a) shows DMS7148 (Variant 6); (Analysis Notes: Measured mass matches theexpected mass with a single disulphide (15245.88)); b) shows DMS7149(Variant 7) (Analysis Notes: Measured mass match residues 24-142(12860.56), 26-142 (12603.26) and 28-142 (12390.97), all with singledisulphides. Each peak has an associated peak that is +42 Da—mostprobably acetylated.); c) shows DMS7150 (Variant 8) (Analysis Notes:Measured mass matches residues 26-142 with a single disulphide(12603.26).); d) shows DMS7151 (Variant 9) (Analysis Notes: Unable toaccount for 12960, 12890.5, 12603 and 12391.50 are close matches toresidues 24-142, 26-142 and 28-142 respectively, each with a singledisulphide (12862.53, 12605.24 and 12392.94). However, there is a 2 Damass discrepancy between the measured and calculated masses.); e) showsDMS7152 (Variant 10) (Analysis Notes: 12790.5 and 12320.5 match residues24-142 and 28-142 respectively with single disulphides (12790.42 and12320.84).) f) shows DMS7161 (Variant 11).

FIG. 6: Shows the results of an assay of GLP-1-ALBUDAB™ fusion variant6.

FIG. 7: Shows the results of an assay of GLP-1-ALBUDAB™ fusion variant11.

DETAILED DESCRIPTION OF THE DISCLOSURE

Within this specification the disclosure has been described, withreference to embodiments, in a way which enables a clear and concisespecification to be written. It is intended and should be appreciatedthat embodiments may be variously combined or separated without partingfrom the disclosure.

As used herein, “peptide” refers to about two to about 50 amino acidsthat are joined together via peptide bonds.

As used herein, “polypeptide” refers to at least about 50 amino acidsthat are joined together by peptide bonds. Polypeptides generallycomprise tertiary structure and fold into functional domains.

As used herein, a peptide or polypeptide (e.g. a domain antibody (dAb))that is “resistant to protease degradation” is not substantiallydegraded by a protease when incubated with the protease under conditionssuitable for protease activity. A polypeptide (e.g., a dAb) is notsubstantially degraded when no more than about 25%, no more than about20%, no more than about 15%, no more than about 14%, no more than about13%, no more than about 12%, no more than about 11%, no more than about10%, no more than about 9%, no more than about 8%, no more than about7%, no more than about 6%, no more than about 5%, no more than about 4%,no more than about 3%, no more that about 2%, no more than about 1%, orsubstantially none of the protein is degraded by protease aboutincubation with the protease for about one hour at a temperaturesuitable for protease activity. For example at 37 or 50 degrees C.Protein degradation can be assessed using any suitable method, forexample, by SDS-PAGE or by functional assay (e.g., ligand binding) asdescribed herein.

As used herein, “display system” refers to a system in which acollection of polypeptides or peptides are accessible for selectionbased upon a desired characteristic, such as a physical, chemical orfunctional characteristic. The display system can be a suitablerepertoire of polypeptides or peptides (e.g., in a solution, immobilizedon a suitable support). The display system can also be a biochemicalsystem that employs a cellular expression system (e.g., expression of alibrary of nucleic acids in, e.g., transformed, infected, transfected ortransduced cells and display of the encoded polypeptides on the surfaceof the cells) or an acellular expression system (e.g., emulsioncompartmentalization and display). Preferred display systems link thecoding function of a nucleic acid and physical, chemical and/orfunctional characteristics of a polypeptide or peptide encoded by thenucleic acid. When such a display system is employed, polypeptides orpeptides that have a desired physical, chemical and/or functionalcharacteristic can be selected and a nucleic acid encoding the selectedpolypeptide or peptide can be readily isolated or recovered. A number ofdisplay systems that link the coding function of a nucleic acid andphysical, chemical and/or functional characteristics of a polypeptide orpeptide are known in the art, for example, bacteriophage display (phagedisplay), ribosome display, emulsion compartmentalization and display,yeast display, puromycin display, bacterial display, display on plasmid,covalent display and the like. (See, e.g., EP 0436597 (Dyax), U.S. Pat.No. 6,172,197 (McCafferty et al.), U.S. Pat. No. 6,489,103 (Griffiths etal.).)

As used herein, “repertoire” refers to a collection of polypeptides orpeptides that are characterized by amino acid sequence diversity. Theindividual members of a repertoire can have common features, such ascommon structural features (e.g., a common core structure) and/or commonfunctional features (e.g., capacity to bind a common ligand (e.g., ageneric ligand or a target ligand)).

As used herein, “functional” describes a polypeptide or peptide that hasbiological activity, such as specific binding activity. For example, theterm “functional polypeptide” includes an antibody or antigen-bindingfragment thereof that binds a target antigen through its antigen-bindingsite, and an enzyme that binds its substrate(s).

As used herein, “generic ligand” refers to a ligand that binds asubstantial portion (e.g., substantially all) of the functional membersof a given repertoire. A generic ligand (e.g., a common generic ligand)can bind many members of a given repertoire even though the members maynot have binding specificity for a common target ligand. In general, thepresence of a functional generic ligand-binding site on a polypeptide(as indicated by the ability to bind a generic ligand) indicates thatthe polypeptide is correctly folded and functional. Suitable examples ofgeneric ligands include superantigens, antibodies that bind an epitopeexpressed on a substantial portion of functional members of arepertoire, and the like.

“Superantigen” is a term of art that refers to generic ligands thatinteract with members of the immunoglobulin superfamily at a site thatis distinct from the target ligand-binding sites of these proteins.Staphylococcal enterotoxins are examples of superantigens which interactwith T-cell receptors. Superantigens that bind antibodies includeProtein G, which binds the IgG constant region (Bjorck and Kronvall, J.Immunol., 133:969 (1984)); Protein A which binds the IgG constant regionand V_(H) domains (Forsgren and Sjoquist, J. Immunol., 97:822 (1966));and Protein L which binds V_(L) domains (Bjorck, J. Immunol., 140:1194(1988)).

As used herein, “target ligand” refers to a ligand which is specificallyor selectively bound by a polypeptide or peptide. For example, when apolypeptide is an antibody or antigen-binding fragment thereof, thetarget ligand can be any desired antigen or epitope, and when apolypeptide is an enzyme, the target ligand can be any desiredsubstrate. Binding to the target antigen is dependent upon thepolypeptide or peptide being functional.

As used herein, “antibody format” refers to any suitable polypeptidestructure in which an antibody variable domain can be incorporated so asto confer binding specificity for antigen on the structure. A variety ofsuitable antibody formats are known in the art, such as, chimericantibodies, humanized antibodies, human antibodies, single chainantibodies, bispecific antibodies, antibody heavy chains, antibody lightchains, homodimers and heterodimers of antibody heavy chains and/orlight chains, antigen-binding fragments of any of the foregoing (e.g., aFv fragment (e.g., single chain Fv (scFv), a disulfide bonded Fv), a Fabfragment, a Fab′ fragment, a F(ab′)2 fragment), a single antibodyvariable domain (e.g., adAb, V_(H), V_(HH), V_(L)), and modifiedversions of any of the foregoing (e.g., modified by the covalentattachment of polyethylene glycol or other suitable polymer).

The phrase “immunoglobulin single variable domain” refers to an antibodyvariable domain (V_(H), V_(HH), V_(L)) that specifically binds anantigen or epitope independently of other V regions or domains. Animmunoglobulin single variable domain can be present in a format (e.g.,homo- or hetero-multimer) with other variable regions or variabledomains where the other regions or domains are not required for antigenbinding by the single immunoglobulin variable domain (i.e., where theimmunoglobulin single variable domain binds antigen independently of theadditional variable domains). A “domain antibody” or “dAb” is the sameas an “immunoglobulin single variable domain” as the term is usedherein. An immunoglobulin single variable domain is preferably a humanantibody variable domain, but also includes single antibody variabledomains from other species such as rodent (for example, as disclosed inWO 00/29004, the contents of which are incorporated herein by referencein their entirety), nurse shark and Camelid V_(HH) dAbs. Camelid V_(HH)are immunoglobulin single variable domain polypeptides that are derivedfrom species including camel, llama, alpaca, dromedary, and guanaco,which produce heavy chain antibodies naturally devoid of light chains.

A “domain” is a folded protein structure which has tertiary structureindependent of the rest of the protein. Generally, domains areresponsible for discrete functional properties of proteins, and in manycases may be added, removed or transferred to other proteins withoutloss of function of the remainder of the protein and/or of the domain. A“single antibody variable domain” is a folded polypeptide domaincomprising sequences characteristic of antibody variable domains. Ittherefore includes complete antibody variable domains and modifiedvariable domains, for example, in which one or more loops have beenreplaced by sequences which are not characteristic of antibody variabledomains, or antibody variable domains which have been truncated orcomprise N- or C-terminal extensions, as well as folded fragments ofvariable domains which retain at least the binding activity andspecificity of the full-length domain.

The term “library” refers to a mixture of heterogeneous polypeptides ornucleic acids. The library is composed of members, each of which has asingle polypeptide or nucleic acid sequence. To this extent, “library”is synonymous with “repertoire.” Sequence differences between librarymembers are responsible for the diversity present in the library. Thelibrary may take the form of a simple mixture of polypeptides or nucleicacids, or may be in the form of organisms or cells, for examplebacteria, viruses, animal or plant cells and the like, transformed witha library of nucleic acids. Preferably, each individual organism or cellcontains only one or a limited number of library members.Advantageously, the nucleic acids are incorporated into expressionvectors, in order to allow expression of the polypeptides encoded by thenucleic acids. In a preferred aspect, therefore, a library may take theform of a population of host organisms, each organism containing one ormore copies of an expression vector containing a single member of thelibrary in nucleic acid form which can be expressed to produce itscorresponding polypeptide member. Thus, the population of host organismshas the potential to encode a large repertoire of diverse polypeptides.

A “universal framework” is a single antibody framework sequencecorresponding to the regions of an antibody conserved in sequence asdefined by Kabat (“Sequences of Proteins of Immunological Interest”, USDepartment of Health and Human Services, 1991) or corresponding to thehuman germline immunoglobulin repertoire or structure as defined byChothia and Lesk, (1987) J. Mol. Biol. 196:910-917. The disclosureprovides for the use of a single framework, or a set of such frameworks,which has been found to permit the derivation of virtually any bindingspecificity though variation in the hypervariable regions alone.

Amino acid and nucleotide sequence alignments and homology, similarityor identity, as defined herein are preferably prepared and determinedusing the algorithm BLAST 2 Sequences, using default parameters(Tatusova, T. A. et al., FEMS Microbial Lett, 174:187-188 (1999)).

The disclosure relates to a method of selection of protease resistantpeptides and polypeptides that have a desired biological activity. Atleast two selective pressures are used in the method to produce anefficient process for selecting polypeptides that are highly stable andresistant to protease degradation, and that have desired biologicalactivity. As described herein, protease resistant peptides andpolypeptides generally retain biological activity. In contrast, proteasesensitive peptides and polypeptides are cleaved or digested by proteasein the methods described herein, and therefore, lose their biologicalactivity. Accordingly, protease resistant peptides or polypeptides aregenerally selected based on their biological activity, such as bindingactivity.

The methods described herein provide several advantages. For example, asdisclosed and exemplified herein, peptides or polypeptides that areselected for resistance to proteolytic degradation by one protease(e.g., trypsin), are also resistant to degradation by other proteases(e.g., elastase, leucozyme). In addition, protease resistance correlateswith a higher melting temperature (Tm) of the peptide or polypeptide.Higher melting temperatures are indicative of more stable peptides andpolypeptides. Resistance to protease degradation also correlates withhigh affinity binding to target ligands. Thus, the methods describedherein provide an efficient way to select, isolate and/or recoverpolypeptides that have a desired biological activity and that are wellsuited for in vivo therapeutic and/or diagnostic uses because they areprotease resistant and stable.

Selection Methods

In one aspect, the disclosure is a method for selecting, isolatingand/or recovering a peptide or polypeptide from a library or arepertoire of peptides and polypeptides (e.g., a display system) that isresistant to degradation by a protease (e.g., one or more proteases).Preferably, the method is a method for selecting, isolating and/orrecovering a polypeptide from a library or a repertoire of peptides andpolypeptides (e.g., a display system) that is resistant to degradationby a protease (e.g., one or more proteases). Generally, the methodcomprises providing a library or repertoire of peptides or polypeptides,incubating the library or repertoire in the presence of a protease (e.g.a bacterial protease or an exogenously added protease such as trypsin,elastase, leucozyme, pancreatin, sputum) under conditions suitable forprotease activity, and selecting, isolating and/or recovering a peptideor polypeptide that is resistant to degradation by the protease and hasa desired biological activity. Peptides or polypeptides that aredegraded by a protease generally have reduced biological activity orlose their biological activity due to the activity of protease.Accordingly, peptides or polypeptides that are resistant to proteasedegradation can be selected, isolated and/or recovered using the methodbased on their biological activity, such as binding activity (e.g.,binding a general ligand, binding a specific ligand, binding asubstrate), catalytic activity or other biological activity.

As described and exemplified herein, protease resistant dAbs generallybind their target ligand with high affinity. Thus, in another aspect,disclosure is a method for selecting, isolating and/or recovering apeptide or polypeptide that binds a ligand, preferably a target ligand,with high affinity. Preferably, the method is a method for selecting,isolating and/or recovering a polypeptide that binds a ligand,preferably a target ligand, with high affinity. Generally, the methodcomprises providing a library or repertoire of peptides or polypeptides,combining the library or repertoire with a protease (e.g., trypsin,elastase, leucozyme, pancreatin, sputum) under conditions suitable forprotease activity, and selecting, isolating and/or recovering a peptideor polypeptide that binds a ligand (e.g., target ligand). As describedherein, the method may also comprise incubating the library orrepertoire of peptides or polypeptides under conditions suitable foractivity of a protease which is endogenous to the display system such asa bacterial protease (wherein the display system includes expression inbacteria). Because the library or repertoire has been exposed toprotease under conditions where protease sensitive peptides orpolypeptides will be digested, the activity of protease can eliminatethe less stable polypeptides that have low binding affinity, and therebyproduce a collection of high affinity binding peptides or polypeptides.For example, the selected peptide of polypeptide can bind its targetligand with an affinity (KD; KD=K_(off)(kd)/K_(on)(ka) as determined bysurface plasmon resonance) of 1 μM or stronger, preferably about 500 nMto about 0.5 pM. For example, the high affinity peptide of polypeptidecan bind target ligand with an affinity of about 500 nM, about 100 nM,about 10 nM, about 1 nM, about 500 pM, about 100 pM, about 10 pM, about1 pM or about 0.5 pM. Peptides and polypeptides that are resistant toproteases are believed to have a lower entropy and/or a higherstabilization energy. Thus, the correlation between protease resistanceand high affinity binding may be related to the compactness andstability of the surfaces of the peptides and polypeptides selected bythe method of the disclosure.

The library or repertoire of peptides or polypeptides is combined with aprotease (e.g., one or more proteases) under conditions suitable forproteolytic activity of the protease. Conditions that are suitable forproteolytic activity of protease, and biological preparations ormixtures that contain proteolytic activity, are well-known in the art orcan be readily determined by a person of ordinary skill in the art. Ifdesired, suitable conditions can be identified or optimized, forexample, by assessing protease activity under a range of pH conditions,protease concentrations, temperatures and/or by varying the amount oftime the library or repertoire and the protease are permitted to react.For example, in some embodiments, the ratio (on a mole/mole basis) ofprotease, eg trypsin, to peptide or polypeptide (eg, variable domain) is800 to 80,000 (eg, 8,000 to 80,000) protease:peptide or polypeptide, egwhen 10 micrograms/ml of protease is used, the ratio is 800 to 80,000protease:peptide or polypeptide; or when 100 micrograms/ml of proteaseis used, the ratio is 8,000 to 80,000 protease:peptide or polypeptide.In one embodiment the ratio (on a weight/weight, eg microgram/microgrambasis) of protease (eg, trypsin) to peptide or polypeptide (eg, variabledomain) is 1,600 to 160,000 (eg, 16,000 to 160,000) protease:peptide orpolypeptide eg when 10 micrograms/ml of protease is used, the ratio is1,600 to 160,000 protease:peptide or polypeptide; or when 100micrograms/ml of protease is used, the ratio is 16,000 to 160,000protease:peptide or polypeptide. In one embodiment, the protease is usedat a concentration of at least 100 or 1000 micrograms/ml and theprotease: peptide ratio (on a mole/mole basis) of protease, eg trypsin,to peptide or polypeptide (eg, variable domain) is 8,000 to 80,000protease:peptide or polypeptide. In one embodiment, the protease is usedat a concentration of at least 10 micrograms/ml and the protease:peptide ratio (on a mole/mole basis) of protease, eg trypsin, to peptideor polypeptide (eg, variable domain) is 800 to 80,000 protease:peptideor polypeptide. In one embodiment the ratio (on a weight/weight, egmicrogram/microgram basis) of protease (eg, trypsin) to peptide orpolypeptide (eg, variable domain) is 1600 to 160,000 protease:peptide orpolypeptide eg when C is 10 micrograms/ml; or when C or C′ is 100micrograms/ml, the ratio is 16,000 to 160,000 protease:peptide orpolypeptide. In one embodiment, the concentration (c or c′) is at least100 or 1000 micrograms/ml protease. For testing an individual orisolated peptide or polypeptide (eg, an immunoglobulin variable domain),eg one that has already been isolated from a repertoire or library, aprotease can be added to a solution of peptide or polypeptide in asuitable buffer (e.g., PBS) to produce a peptide or polypeptide/proteasesolution, such as a solution of at least about 0.01% (w/w)protease/peptide or polypeptide, about 0.01% to about 5% (w/w)protease/peptide or polypeptide, about 0.05% to about 5% (w/w)protease/peptide or polypeptide, about 0.1% to about 5% (w/w)protease/peptide or polypeptide, about 0.5% to about 5% (w/w)protease/peptide or polypeptide, about 1% to about 5% (w/w)protease/peptide or polypeptide, at least about 0.01% (w/w)protease/peptide or polypeptide, at least about 0.02% (w/w)protease/peptide or polypeptide, at least about 0.03% (w/w)protease/peptide or polypeptide, at least about 0.04% (w/w)protease/peptide or polypeptide, at least about 0.05% (w/w)protease/peptide or polypeptide, at least about 0.06% (w/w)protease/peptide or polypeptide, at least about 0.07% (w/w)protease/peptide or polypeptide, at least about 0.08% (w/w)protease/peptide or polypeptide, at least about 0.09% (w/w)protease/peptide or polypeptide, at least about 0.1% (w/w)protease/peptide or polypeptide, at least about 0.2% (w/w)protease/peptide or polypeptide, at least about 0.3% (w/w)protease/peptide or polypeptide, at least about 0.4% (w/w)protease/peptide or polypeptide, at least about 0.5% (w/w)protease/peptide or polypeptide, at least about 0.6% (w/w)protease/peptide or polypeptide, at least about 0.7% (w/w)protease/peptide or polypeptide, at least about 0.8% (w/w)protease/peptide or polypeptide, at least about 0.9% (w/w)protease/peptide or polypeptide, at least about 1% (w/w)protease/peptide or polypeptide, at least about 2% (w/w)protease/peptide or polypeptide, at least about 3% (w/w)protease/peptide or polypeptide, at least about 4% (w/w)protease/peptide or polypeptide, or about 5% (w/w) protease/peptide orpolypeptide. The mixture can be incubated at a suitable temperature forprotease activity (e.g., room temperature, about 37° C.) and samples canbe taken at time intervals (e.g., at 1 hour, 2 hours, 3 hours, etc.).The samples can be analyzed for protein degradation using any suitablemethod, such as SDS-PAGE analysis or ligand binding, and the results canbe used to establish a time course of degradation.

Any desired protease or proteases can be used in the methods describedherein. For example, a single protease, any desired combination ofdifferent proteases, or any biological preparation, biological extract,or biological homogenate that contains proteolytic activity can be used.It is not necessary that the identity of the protease or proteases thatare used be known. Suitable examples of proteases that can be used aloneor in any desired combination include serine protease, cysteineprotease, aspartate proteases, thiol proteases, matrix metalloprotease,carboxypeptidase (e.g., carboxypeptidase A, carboxypeptidase B),trypsin, chymotrypsin, pepsin, papain, elastase, leucozyme, pancreatin,thrombin, plasmin, cathepsins (e.g., cathepsin G), proteinase (e.g.,proteinase 1, proteinase 2, proteinase 3), thermolysin, chymosin,enteropeptidase, caspase (e.g., caspase 1, caspase 2, caspase 4, caspase5, caspase 9, caspase 12, caspase 13), calpain, ficain, clostripain,actinidain, bromelain, separase, dipeptidyl aminopeptidase IV and thelike. Suitable biological extracts, homogenates and preparations thatcontains proteolytic activity include serum, sputum, mucus (e.g.,gastric mucus, nasal mucus, bronchial mucus), bronchoalveolar lavage,lung homogenate, lung extract, pancreatic extract, gastric fluid,saliva, tears and the like. In one embodiment, the protease is one foundin the eye and/or tears. The protease is used in an amount suitable forproteolytic degradation to occur. For example, as described herein,protease can be used at about 0.01% to about 5% (w/w, protease/peptideor polypeptide). When protease is combined with a display system thatcomprises the repertoire of peptides or polypeptides (e.g., a phagedisplay system), for example, the protease can be used at aconcentration of about 10 μg/ml to about 3 mg/ml, about 10 μg/ml, about20 μg/ml, about 30 μg/ml, about 40 μg/ml, about 50 μg/ml, about 60μg/ml, about 70 μg/ml, about 80 μg/ml, about 90 μg/ml, about 100 μg/ml,about 200 μg/ml, about 300 μg/ml, about 400 μg/ml, about 500 μg/ml,about 600 μg/ml, about 700 μg/ml, about 800 μg/ml, about 900 μg/ml,about 1000 μg/ml, about 1.5 mg/ml, about 2 mg/ml, about 2.5 mg/ml orabout 3 mg/ml. Suitable concentrations are about 10 μg/ml to 1 mg/ml, 10μg/ml to 100, 90, 80, 70, 60, 50 or 40 μg/ml, or 10, 20, 30, 40 or 50μg/ml to 100, 90, 80, 70, 60 μg/ml.

The protease is incubated with the collection of peptides orpolypeptides (library or repertoire) at a temperature that is suitablefor activity of the protease. For example, the protease and collectionof peptides or polypeptides can be incubated at a temperature of about20° C. to about 40° C. (e.g., at room temperature, about 20° C., about21° C., about 22° C., about 23° C., about 24° C., about 25° C., about26° C., about 27° C., about 28° C., about 29° C., about 30° C., about31° C., about 32° C., about 33° C., about 34° C., about 35° C., about36° C., about 37° C., about 38° C., about 39° C., about 40° C.). Theprotease and the collection of peptides or polypeptides are incubatedtogether for a period of time sufficient for proteolytic degradation tooccur. For example, the collection of peptides or polypeptides can beincubated together with protease for about 30 minutes to about 24 orabout 48 hours. In some examples, the collection of peptides orpolypeptides is incubated together with protease overnight, or for atleast about 30 minutes, about 1 hour, about 1.5 hours, about 2 hours,about 3 hours, about 4 hours, about 5 hours, about 6 hours, about 7hours, about 8 hours, about 9 hours, about 10 hours, about 11 hours,about 12 hours, about 13 hours, about 14 hours, about 15 hours, about 16hours, about 17 hours, about 18 hours, about 19 hours, about 20 hours,about 21 hours, about 22 hours, about 23 hours, about 24 hours, about 48hours, or longer.

It is generally desirable, at least in early selection rounds (e.g. whena display system is used), that the protease results in a reduction inthe number of clones that have the desired biological activity that isselected for by at least one order of magnitude, in comparison toselections that do not include incubation with protease. In particularexamples, the amount of protease and conditions used in the methods aresufficient to reduce the number of recovered clones by at least aboutone log (a factor of 10), at least about 2 logs (a factor of 100), atleast about 3 logs (a factor of 1000) or at least about 4 logs (a factorof 10,000). Suitable amounts of protease and incubation conditions thatwill result in the desired reduction in recovered clones can be easilydetermined using conventional methods and/or the guidance providedherein.

The protease and collection of peptides or polypeptides can be combinedand incubated using any suitable method (e.g., in vitro, in vivo or exvivo). For example, the protease and collection of peptides orpolypeptides can be combined in a suitable container and heldstationary, rocked, shaken, swirled or the like, at a temperaturesuitable for protease activity. If desired, the protease and collectionof peptides or polypeptides can be combined in an in vivo or ex vivosystem, such as by introducing the collection of polypeptides (e.g., aphage display library or repertoire) into a suitable animal (e.g., amouse), and after sufficient time for protease activity has passed,recovering the collection of peptides or polypeptides. In anotherexample, an organ or tissue is perfused with the collection ofpolypeptides (e.g., a phage display library or repertoire), and aftersufficient time for protease activity has passed, the collection ofpolypeptides is recovered.

Following incubation, a protease resistant peptide or polypeptide can beselected based on a desired biological activity, such as a bindingactivity. If desired, a protease inhibitor can be added beforeselection. Any suitable protease inhibitor (or combination of two ormore protease inhibitors) that will not substantially interfere with theselection method can be used. Examples of suitable protease inhibitorsinclude, α1-anti-trypsin, α2-macroglobulin, amastatin, antipain,antithrombin III, aprotinin, 4-(2-Aminoethyl) benzenesulfonyl fluoridehydrochloride (AEBSF), (4-Amidino-Phenyl)-Methane-Sulfonyl Fluoride(APMSF), bestatin, benzamidine, chymostatin, 3,4-Dichloroisocoumarin,diisoproply fluorophosphate (DIFP), E-64, ethylenediamine tetraacedicacid (EDTA), elastatinal, leupeptin, N-Ethylmaleimide, phenylmethylsulfonylfluoride (PMSF), pepstatin, 1,10-Phenanthroline, phosphoramidon,serine protease inhibitors, N-tosyl-L-lysine-chloromethyl ketone (TLCK),Na-Tosyl-Phe-chloromethylketone (TPCK) and the like. In addition, manypreparations that contain inhibitors of several classes of proteases arecommercially available (e.g., Roche Complete Protease Inhibitor CocktailTablets™ (Roche Diagnostics Corporation; Indianapolis, Ind., USA), whichinhibits chymotrypsin, thermolysin, papain, pronase, pancreatic extractand trypsin).

A protease resistant peptide or polypeptide can be selected using adesired biological activity selection method, which allows peptides andpolypeptides that have the desired biological activity to bedistinguished from and selected over peptides and polypeptides that donot have the desired biological activity. Generally, peptides orpolypeptides that have been digested or cleaved by protease loose theirbiological activity, while protease resistant peptides or polypeptidesremain functional. Thus, suitable assays for biological activity can beused to select protease resistant peptides or polypeptides. For example,a common binding function (e.g., binding of a general ligand, binding ofa specific ligand, or binding of a substrate) can be assessed using asuitable binding assay (e.g., ELISA, panning). For example, polypeptidesthat bind a target ligand or a generic ligand, such as protein A,protein L or an antibody, can be selected, isolated, and/or recovered bypanning or using a suitable affinity matrix. Panning can be accomplishedby adding a solution of ligand (e.g., generic ligand, target ligand) toa suitable vessel (e.g., tube, petri dish) and allowing the ligand tobecome deposited or coated onto the walls of the vessel. Excess ligandcan be washed away and polypeptides (e.g., a phage display library) canbe added to the vessel and the vessel maintained under conditionssuitable for the polypeptides to bind the immobilized ligand. Unboundpolypeptide can be washed away and bound polypeptides can be recoveredusing any suitable method, such as scraping or lowering the pH, forexample.

When a phage display system is used, binding can be tested in a phageELISA. Phage ELISA may be performed according to any suitable procedure.In one example, populations of phage produced at each round of selectioncan be screened for binding by ELISA to the selected target ligand orgeneric ligand, to identify phage that display protease resistantpeptides or polypeptides. If desired, soluble peptides and polypeptidescan be tested for binding to target ligand or generic ligand, forexample by ELISA using reagents, for example, against a C- or N-terminaltag (see for example Winter et al. (1994) Ann. Rev. Immunology 12,433-55 and references cited therein). The diversity of the selectedphage may also be assessed by gel electrophoresis of PCR products (Markset al. 1991, supra; Nissim et al. 1994 supra), probing (Tomlinson etal., 1992)J. Mol. Biol. 227, 776) or by sequencing of the vector DNA.

Protease resistant peptides and polypeptides can also be selected, forexample, based on catalytic activity, which can be measured using acatalytic activity assay (e.g., proteolytic activity assay,phosphotransferase assay, phosphohydrolase assay, polymerase activityassay).

The protease resistant peptide or polypeptide (e.g., single antibodyvariable domain) can have binding specificity for a generic ligand orany desired target ligand, such as human or animal proteins, includingcytokines, growth factors, cytokine receptors, growth factor receptors,enzymes (e.g., proteases), co-factors for enzymes, DNA binding proteins,lipids and carbohydrates. Suitable targets antigens, includingcytokines, growth factors, cytokine receptors, growth factor receptorsand other proteins as described herein. It will be appreciated that thislist is by no means exhaustive.

In some embodiments, the protease resistant peptide or polypeptide bindsa target in pulmonary tissue, such as a target selected from the groupconsisting of TNFR1, IL-1, IL-1R, IL-4, IL-4R, IL-5, IL-6, IL-6R, IL-8,IL-8R, IL-9, IL-9R, IL-10, IL-12 IL-12R, IL-13, IL-13Rα1, IL-13Rα2,IL-15, IL-15R, IL-16, IL-17R, IL-17, IL-18, IL-18R, IL-23 IL-23R, IL-25,CD2, CD4, CD11a, CD23, CD25, CD27, CD28, CD30, CD40, CD40L, CD56, CD138,ALK5, EGFR, FcER1, TGFb, CCL2, CCL18, CEA, CR8, CTGF, CXCL12 (SDF-1),chymase, FGF, Furin, Endothelin-1, Eotaxins (e.g., Eotaxin, Eotaxin-2,Eotaxin-3), GM-CSF, ICAM-1, ICOS, IgE, IFNa, I-309, integrins,L-selectin, MIF, MIP4, MDC, MCP-1, MMPs, neutrophil elastase,osteopontin, OX-40, PARC, PD-1, RANTES, SCF, SDF-1, siglec8, TARC, TGFb,Thrombin, Tim-1, TNF, TRANCE, Tryptase, VEGF, VLA-4, VCAM, α4β7, CCR2,CCR3, CCR4, CCR5, CCR7, CCR8, alphavbeta6, alphavbeta8, cMET, CD8, vWF,amyloid proteins (e.g., amyloid alpha), MMP12, PDK1, and IgE.

When a display system (e.g., a display system that links coding functionof a nucleic acid and functional characteristics of the peptide orpolypeptide encoded by the nucleic acid) is used in the methodsdescribed herein it is frequently advantageous to amplify or increasethe copy number of the nucleic acids that encode the selected peptidesor polypeptides. This provides an efficient way of obtaining sufficientquantities of nucleic acids and/or peptides or polypeptides foradditional rounds of selection, using the methods described herein orother suitable methods, or for preparing additional repertoires (e.g.,affinity maturation repertoires). Thus, in some embodiments, the methodsof the disclosure comprises using a display system (e.g., that linkscoding function of a nucleic acid and functional characteristics of thepeptide or polypeptide encoded by the nucleic acid, such as phagedisplay) and further comprises amplifying or increasing the copy numberof a nucleic acid that encodes a selected peptide or polypeptide.Nucleic acids can be amplified using any suitable methods, such as byphage amplification, cell growth or polymerase chain reaction.

The methods described herein can be used as part of a program toisolated protease resistant peptides or polypeptides that can comprise,if desired, other suitable selection methods. In these situations, themethods described herein can be employed at any desired point in theprogram, such as before or after other selection methods are used. Themethods described herein can also be used to provide two or more roundsof selection, as described and exemplified herein.

In another aspect, the disclosure is a method of producing a repertoireof protease resistant peptides or polypeptides. The method comprisesproviding a repertoire of peptides or polypeptides; combining therepertoire of peptides or polypeptides and a protease under suitableconditions for protease activity; and recovering a plurality of peptidesor polypeptides that have a desired biological activity, whereby arepertoire of protease resistant peptides or polypeptides is produced.Preferably, the plurality of peptides or polypeptides that have adesired biological activity are recovered based on a binding activity,such as binding to a generic ligand or a target ligand. Proteases,display systems, conditions for protease activity, and methods forselecting peptides or polypeptides that are suitable for use in themethod are described herein with respect to the other methods of thedisclosure.

In some embodiments, a display system (e.g., a display system that linkscoding function of a nucleic acid and functional characteristics of thepeptide or polypeptide encoded by the nucleic acid) that comprises arepertoire of peptides or polypeptides is used, and the method furthercomprises amplifying or increasing the copy number of the nucleic acidsthat encode the plurality of selected peptides or polypeptides. Nucleicacids can be amplified using any suitable method, such as by phageamplification, cell growth or polymerase chain reaction. In oneembodiment, the display system is bacteriophage display and theamplification is through expression in E. Coli. In this embodiment,protease expression in E. Coli can provide the protease for selection ofprotease resistant peptides or polypeptides.

In particular embodiment, the disclosure is a method of producing arepertoire of protease resistant polypeptides that comprise dAbs. Themethod comprises providing a repertoire of polypeptides that comprisedAbs; combining the repertoire of peptides or polypeptides and aprotease (e.g., trypsin, elastase, leucozyme) under suitable conditionsfor protease activity; and recovering a plurality of polypeptides thatcomprise dAbs that have binding specificity for a generic ligand (e.g.,protein A, protein G, protein L) or a target ligand. The method can beused to produce a naïve repertoire, or a repertoire that is biasedtoward a desired binding specificity, such as an affinity maturationrepertoire based on a parental dAb that has binding specificity for adesired target ligand.

Polypeptide Display Systems

Preferably, the repertoire or library of peptides or polypeptidesprovided for use in the methods of the disclosure comprise a suitabledisplay system. The display system preferably resists degradation byprotease (e.g., a single protease or a combination of proteases, and anybiological extract, homogenate or preparation that contains proteolyticactivity (e.g., serum, sputum, mucus (e.g., gastric mucus, nasal mucus,bronchial mucus), bronchoalveolar lavage, lung homogenate, lung extract,pancreatic extract, gastric fluid, saliva, tears and the like). Thedisplay system and the link between the display system and the displayedpolypeptide is preferably at least as resistant to protease as the moststable peptides or polypeptides of the repertoire. This allows a nucleicacid that encodes a selected displayed polypeptide to be easily isolatedand/or amplified.

In one example, a protease resistant peptide or polypeptide can beselected, isolated and/or recovered from a repertoire of peptides orpolypeptides that is in solution, or is covalently or noncovalentlyattached to a suitable surface, such as plastic or glass (e.g.,microtiter plate, polypeptide array such as a microarray). For examplean array of peptides on a surface in a manner that places each distinctlibrary member (e.g., unique peptide sequence) at a discrete, predefinedlocation in the array can be used. The identity of each library memberin such an array can be determined by its spatial location in the array.The locations in the array where binding interactions between a targetligand, for example, and reactive library members occur can bedetermined, thereby identifying the sequences of the reactive members onthe basis of spatial location. (See, e.g., U.S. Pat. No. 5,143,854, WO90/15070 and WO 92/10092.)

Preferably, the methods employ a display system that links the codingfunction of a nucleic acid and physical, chemical and/or functionalcharacteristics of the polypeptide encoded by the nucleic acid. Such adisplay system can comprise a plurality of replicable genetic packages,such as bacteriophage or cells (bacteria). Preferably, the displaysystem comprises a library, such as a bacteriophage display library.Bacteriophage display is a particularly preferred display system.

A number of suitable bacteriophage display systems (e.g., monovalentdisplay and multivalent display systems) have been described. (See,e.g., Griffiths et al., U.S. Pat. No. 6,555,313 B1 (incorporated hereinby reference); Johnson et al., U.S. Pat. No. 5,733,743 (incorporatedherein by reference); McCafferty et al., U.S. Pat. No. 5,969,108(incorporated herein by reference); Mulligan-Kehoe, U.S. Pat. No.5,702,892 (Incorporated herein by reference); Winter, G. et al., Annu.Rev. Immunol. 12:433-455 (1994); Soumillion, P. et al., Appl. Biochem.Biotechnol. 47(2-3):175-189 (1994); Castagnoli, L. et al., Comb. Chem.High Throughput Screen, 4(2):121-133 (2001).) The peptides orpolypeptides displayed in a bacteriophage display system can bedisplayed on any suitable bacteriophage, such as a filamentous phage(e.g., fd, M13, F1), a lytic phage (e.g., T4, T7, lambda), or an RNAphage (e.g., MS2), for example.

Generally, a library of phage that displays a repertoire of peptides orphage polypeptides, as fusion proteins with a suitable phage coatprotein (e.g., fd pIII protein), is produced or provided. The fusionprotein can display the peptides or polypeptides at the tip of the phagecoat protein, or if desired at an internal position. For example, thedisplayed peptide or polypeptide can be present at a position that isamino-terminal to domain 1 of pIII. (Domain 1 of pIII is also referredto as N1.) The displayed polypeptide can be directly fused to pIII(e.g., the N-terminus of domain 1 of pIII) or fused to pIII using alinker. If desired, the fusion can further comprise a tag (e.g., mycepitope, His tag). Libraries that comprise a repertoire of peptides orpolypeptides that are displayed as fusion proteins with a phage coatprotein, can be produced using any suitable methods, such as byintroducing a library of phage vectors or phagemid vectors encoding thedisplayed peptides or polypeptides into suitable host bacteria, andculturing the resulting bacteria to produce phage (e.g., using asuitable helper phage or complementing plasmid if desired). Suitably, inone embodiment of the disclosure, suitable conditions for proteaseexpression in the bacteria are selected. The library of phage can berecovered from the culture using any suitable method, such asprecipitation and centrifugation.

The display system can comprise a repertoire of peptides or polypeptidesthat contains any desired amount of diversity. For example, therepertoire can contain peptides or polypeptides that have amino acidsequences that correspond to naturally occurring polypeptides expressedby an organism, group of organisms, desired tissue or desired cell type,or can contain peptides or polypeptides that have random or randomizedamino acid sequences. If desired, the polypeptides can share a commoncore or scaffold. For example, all polypeptides in the repertoire orlibrary can be based on a scaffold selected from protein A, protein L,protein G, a fibronectin domain, an anticalin, CTLA4, a desired enzyme(e.g., a polymerase, a cellulase), or a polypeptide from theimmunoglobulin superfamily, such as an antibody or antibody fragment(e.g., an antibody variable domain). The polypeptides in such arepertoire or library can comprise defined regions of random orrandomized amino acid sequence and regions of common amino acidsequence. In certain embodiments, all or substantially all polypeptidesin a repertoire are of a desired type, such as a desired enzyme (e.g., apolymerase) or a desired antigen-binding fragment of an antibody (e.g.,human V_(H) or human V_(L)). In preferred embodiments, the polypeptidedisplay system comprises a repertoire of polypeptides wherein eachpolypeptide comprises an antibody variable domain. For example, eachpolypeptide in the repertoire can contain a V_(H), a V_(L) or an Fv(e.g., a single chain Fv). As described herein, the repertoire can be alibrary of polypeptides based on parental molecules such as GLP-1 or itsderivatives such as a dipeptidyl peptidase IV-resistant derivative.

Amino acid sequence diversity can be introduced into any desired regionof a peptide or polypeptide or scaffold using any suitable method. Forexample, amino acid sequence diversity can be introduced into a targetregion, such as a complementarity determining region of an antibodyvariable domain or a hydrophobic domain, by preparing a library ofnucleic acids that encode the diversified polypeptides using anysuitable mutagenesis methods (e.g., low fidelity PCR,oligonucleotide-mediated or site directed mutagenesis, diversificationusing NNK codons) or any other suitable method. If desired, a region ofa polypeptide to be diversified can be randomized.

The size of the polypeptides that make up the repertoire is largely amatter of choice and uniform polypeptide size is not required.Preferably, the polypeptides in the repertoire have at least tertiarystructure (form at least one domain).

Selection/Isolation/Recovery

A protease resistant peptide or polypeptide (e.g., a population ofprotease resistant polypeptides) can be selected, isolated and/orrecovered from a repertoire or library (e.g., in a display system) usingany suitable method. Preferably, a protease resistant polypeptide isselected or isolated based on a selectable characteristic (e.g.,physical characteristic, chemical characteristic, functionalcharacteristic). Suitable selectable functional characteristics includebiological activities of the peptides or polypeptides in the repertoire,for example, binding to a generic ligand (e.g., a superantigen), bindingto a target ligand (e.g., an antigen, an epitope, a substrate), bindingto an antibody (e.g., through an epitope expressed on a peptide orpolypeptide), and catalytic activity. (See, e.g., Tomlinson et al., WO99/20749; WO 01/57065; WO 99/58655.)

In some embodiments, the protease resistant peptide or polypeptide isselected and/or isolated from a library or repertoire of peptides orpolypeptides in which substantially all protease resistant peptides orpolypeptides share a common selectable feature. For example, theprotease resistant peptide or polypeptide can be selected from a libraryor repertoire in which substantially all protease resistant peptides orpolypeptides bind a common generic ligand, bind a common target ligand,bind (or are bound by) a common antibody, or possess a common catalyticactivity. This type of selection is particularly useful for preparing arepertoire of protease resistant peptides or polypeptides that are basedon a parental peptide or polypeptide that has a desired biologicalactivity, for example, when performing affinity maturation of animmunoglobulin single variable domain.

Selection based on binding to a common generic ligand can yield acollection or population of peptides or polypeptides that contain all orsubstantially all of the protease resistant peptides or polypeptidesthat were components of the original library or repertoire. For example,peptides or polypeptides that bind a target ligand or a generic ligand,such as protein A, protein L or an antibody, can be selected, isolatedand/or recovered by panning or using a suitable affinity matrix. Panningcan be accomplished by adding a solution of ligand (e.g., genericligand, target ligand) to a suitable vessel (e.g., tube, petri dish) andallowing the ligand to become deposited or coated onto the walls of thevessel. Excess ligand can be washed away and peptides or polypeptides(e.g., a repertoire that has been incubated with protease) can be addedto the vessel and the vessel maintained under conditions suitable forpeptides or polypeptides to bind the immobilized ligand. Unboundpeptides or polypeptides can be washed away and bound peptides orpolypeptides can be recovered using any suitable method, such asscraping or lowering the pH, for example.

Suitable ligand affinity matrices generally contain a solid support orbead (e.g., agarose) to which a ligand is covalently or noncovalentlyattached. The affinity matrix can be combined with peptides orpolypeptides (e.g., a repertoire that has been incubated with protease)using a batch process, a column process or any other suitable processunder conditions suitable for binding of peptides or polypeptides to theligand on the matrix. Peptides or polypeptides that do not bind theaffinity matrix can be washed away and bound peptides or polypeptidescan be eluted and recovered using any suitable method, such as elutionwith a lower pH buffer, with a mild denaturing agent (e.g., urea), orwith a peptide that competes for binding to the ligand. In one example,a biotinylated target ligand is combined with a repertoire underconditions suitable for peptides or polypeptides in the repertoire tobind the target ligand. Bound peptides or polypeptides are recoveredusing immobilized avidin or streptavidin (e.g., on a bead).

In some embodiments, the generic or target ligand is an antibody orantigen binding fragment thereof. Antibodies or antigen bindingfragments that bind structural features of peptides or polypeptides thatare substantially conserved in the peptides or polypeptides of a libraryor repertoire are particularly useful as generic ligands. Antibodies andantigen binding fragments suitable for use as ligands for isolating,selecting and/or recovering protease resistant peptides or polypeptidescan be monoclonal or polyclonal and can be prepared using any suitablemethod.

Libraries/Repertoires

In other aspects, the disclosure relates to repertoires of proteaseresistant peptides and polypeptides, to libraries that encode proteaseresistant peptides and polypeptides, and to methods for producing suchlibraries and repertoires.

Libraries that encode and/or contain protease resistant peptides andpolypeptides can be prepared or obtained using any suitable method. Thelibrary of the disclosure can be designed to encode protease resistantpeptides or polypeptides based on a peptide or polypeptide of interest(e.g., a peptide or polypeptide selected from a library) or can beselected from another library using the methods described herein. Forexample, a library enriched in protease resistant polypeptides can beprepared using a suitable polypeptide display system.

In one example, a phage display library comprising a repertoire ofdisplayed polypeptides comprising immunoglobulin single variable domains(e.g., V_(H), Vk, Vλ) is combined with a protease under conditionssuitable for protease activity, as described herein. Protease resistantpolypeptides are recovered based on a desired biological activity, suchas a binding activity (e.g., binding generic ligand, binding targetligand) thereby yielding a phage display library enriched in proteaseresistant polypeptides.

In another example, a phage display library comprising a repertoire ofdisplayed polypeptides comprising immunoglobulin single variable domains(e.g., V_(H), Vκ, Vλ) is first screened to identify members of therepertoire that have binding specificity for a desired target antigen. Acollection of polypeptides having the desired binding specificity arerecovered and the collection is combined with protease under conditionssuitable for proteolytic activity, as described herein. A collection ofprotease resistant polypeptides that have the desired target bindingspecificity is recovered, yielding a library enriched in proteaseresistant and high affinity polypeptides. As described herein, proteaseresistance in this selection method correlates with high affinitybinding.

Libraries that encode a repertoire of a desired type of polypeptides canreadily be produced using any suitable method. For example, a nucleicacid sequence that encodes a desired type of polypeptide (e.g., apolymerase, an immunoglobulin variable domain) can be obtained and acollection of nucleic acids that each contain one or more mutations canbe prepared, for example by amplifying the nucleic acid using anerror-prone polymerase chain reaction (PCR) system, by chemicalmutagenesis (Deng et al., J. Biol. Chem., 269:9533 (1994)) or usingbacterial mutator strains (Low et al., J. Mol. Biol., 260:359 (1996)).

In other embodiments, particular regions of the nucleic acid can betargeted for diversification. Methods for mutating selected positionsare also well known in the art and include, for example, the use ofmismatched oligonucleotides or degenerate oligonucleotides, with orwithout the use of PCR. For example, synthetic antibody libraries havebeen created by targeting mutations to the antigen binding loops. Randomor semi-random antibody H3 and L3 regions have been appended to germlineimmunoblulin V gene segments to produce large libraries with unmutatedframework regions (Hoogenboom and Winter (1992) supra; Nissim et al.(1994) supra; Griffiths et al. (1994) supra; DeKruif et al. (1995)supra). Such diversification has been extended to include some or all ofthe other antigen binding loops (Crameri et al. (1996) Nature Med.,2:100; Riechmann et al. (1995) Bio/Technology, 13:475; Morphosys, WO97/08320, supra). In other embodiments, particular regions of thenucleic acid can be targeted for diversification by, for example, atwo-step PCR strategy employing the product of the first PCR as a“mega-primer.” (See, e.g., Landt, O. et al., Gene 96:125-128 (1990).)Targeted diversification can also be accomplished, for example, by SOEPCR. (See, e.g., Horton, R. M. et al., Gene 77:61-68 (1989).)

Sequence diversity at selected positions can be achieved by altering thecoding sequence which specifies the sequence of the polypeptide suchthat a number of possible amino acids (e.g., all 20 or a subset thereof)can be incorporated at that position. Using the IUPAC nomenclature, themost versatile codon is NNK, which encodes all amino acids as well asthe TAG stop codon. The NNK codon is preferably used in order tointroduce the required diversity. Other codons which achieve the sameends are also of use, including the NNN codon, which leads to theproduction of the additional stop codons TGA and TAA. Such a targetedapproach can allow the full sequence space in a target area to beexplored.

Preferred libraries comprise protease resistant polypeptides that aremembers of the immunoglobulin superfamily (e.g., antibodies or portionsthereof). For example the libraries can comprise protease resistantantibody polypeptides that have a known main-chain conformation. (See,e.g., Tomlinson et al., WO 99/20749.) Libraries can be prepared in asuitable plasmid or vector. As used herein, vector refers to a discreteelement that is used to introduce heterologous DNA into cells for theexpression and/or replication thereof. Any suitable vector can be used,including plasmids (e.g., bacterial plasmids), viral or bacteriophagevectors, artificial chromosomes and episomal vectors. Such vectors maybe used for simple cloning and mutagenesis, or an expression vector canbe used to drive expression of the library. Vectors and plasmids usuallycontain one or more cloning sites (e.g., a polylinker), an origin ofreplication and at least one selectable marker gene. Expression vectorscan further contain elements to drive transcription and translation of apolypeptide, such as an enhancer element, promoter, transcriptiontermination signal, signal sequences, and the like. These elements canbe arranged in such a way as to be operably linked to a cloned insertencoding a polypeptide, such that the polypeptide is expressed andproduced when such an expression vector is maintained under conditionssuitable for expression (e.g., in a suitable host cell).

Cloning and expression vectors generally contain nucleic acid sequencesthat enable the vector to replicate in one or more selected host cells.Typically in cloning vectors, this sequence is one that enables thevector to replicate independently of the host chromosomal DNA andincludes origins of replication or autonomously replicating sequences.Such sequences are well known for a variety of bacteria, yeast andviruses. The origin of replication from the plasmid pBR322 is suitablefor most Gram-negative bacteria, the 2 micron plasmid origin is suitablefor yeast, and various viral origins (e.g. SV40, adenovirus) are usefulfor cloning vectors in mammalian cells. Generally, the origin ofreplication is not needed for mammalian expression vectors, unless theseare used in mammalian cells able to replicate high levels of DNA, suchas COS cells.

Cloning or expression vectors can contain a selection gene also referredto as selectable marker. Such marker genes encode a protein necessaryfor the survival or growth of transformed host cells grown in aselective culture medium. Host cells not transformed with the vectorcontaining the selection gene will therefore not survive in the culturemedium. Typical selection genes encode proteins that confer resistanceto antibiotics and other toxins, e.g. ampicillin, neomycin, methotrexateor tetracycline, complement auxotrophic deficiencies, or supply criticalnutrients not available in the growth media.

Suitable expression vectors can contain a number of components, forexample, an origin of replication, a selectable marker gene, one or moreexpression control elements, such as a transcription control element(e.g., promoter, enhancer, terminator) and/or one or more translationsignals, a signal sequence or leader sequence, and the like. Expressioncontrol elements and a signal or leader sequence, if present, can beprovided by the vector or other source. For example, the transcriptionaland/or translational control sequences of a cloned nucleic acid encodingan antibody chain can be used to direct expression.

A promoter can be provided for expression in a desired host cell.Promoters can be constitutive or inducible. For example, a promoter canbe operably linked to a nucleic acid encoding an antibody, antibodychain or portion thereof, such that it directs transcription of thenucleic acid. A variety of suitable promoters for procaryotic (e.g., theβ-lactamase and lactose promoter systems, alkaline phosphatase, thetryptophan (trp) promoter system, lac, tac, T3, T7 promoters for E.coli) and eucaryotic (e.g., simian virus 40 early or late promoter, Roussarcoma virus long terminal repeat promoter, cytomegalovirus promoter,adenovirus late promoter, EG-1a promoter) hosts are available.

In addition, expression vectors typically comprise a selectable markerfor selection of host cells carrying the vector, and, in the case of areplicable expression vector, an origin of replication. Genes encodingproducts which confer antibiotic or drug resistance are commonselectable markers and may be used in procaryotic (e.g., β-lactamasegene (ampicillin resistance), Tet gene for tetracycline resistance) andeucaryotic cells (e.g., neomycin (G418 or geneticin), gpt (mycophenolicacid), ampicillin, or hygromycin resistance genes). Dihydrofolatereductase marker genes permit selection with methotrexate in a varietyof hosts. Genes encoding the gene product of auxotrophic markers of thehost (e.g., LEU2, URA3, HISS) are often used as selectable markers inyeast. Use of viral (e.g., baculovirus) or phage vectors, and vectorswhich are capable of integrating into the genome of the host cell, suchas retroviral vectors, are also contemplated.

Suitable expression vectors for expression in prokaryotic (e.g.,bacterial cells such as E. coli) or mammalian cells include, forexample, a pET vector (e.g., pET-12a, pET-36, pET-37, pET-39, pET-40,Novagen and others), a phage vector (e.g., pCANTAB 5 E, Pharmacia),pRIT2T (Protein A fusion vector, Pharmacia), pCDM8, pCDNA1.1/amp,pcDNA3.1, pRc/RSV, pEF-1 (Invitrogen, Carlsbad, Calif.), pCMV-SCRIPT,pFB, pSG5, pXT1 (Stratagene, La Jolla, Calif.), pCDEF3 (Goldman, L. A.,et al., Biotechniques, 21:1013-1015 (1996)), pSVSPORT (GibcoBRL,Rockville, Md.), pEF-Bos (Mizushima, S., et al., Nucleic Acids Res.,18:5322 (1990)) and the like. Expression vectors which are suitable foruse in various expression hosts, such as prokaryotic cells (E. coli),insect cells (Drosophila Schnieder S2 cells, Sf9), yeast (P.methanolica, P. pastoris, S. cerevisiae) and mammalian cells (eg, COScells) are available.

Preferred vectors are expression vectors that enable the expression of anucleotide sequence corresponding to a polypeptide library member. Thus,selection with generic and/or target ligands can be performed byseparate propagation and expression of a single clone expressing thepolypeptide library member. As described above, the preferred selectiondisplay system is bacteriophage display. Thus, phage or phagemid vectorsmay be used. The preferred vectors are phagemid vectors which have an E.coli. origin of replication (for double stranded replication) and also aphage origin of replication (for production of single-stranded DNA). Themanipulation and expression of such vectors is well known in the art(Hoogenboom and Winter (1992) supra; Nissim et al. (1994) supra).Briefly, the vector can contain a β-lactamase gene to confer selectivityon the phagemid and a lac promoter upstream of an expression cassettethat can contain a suitable leader sequence, a multiple cloning site,one or more peptide tags, one or more TAG stop codons and the phageprotein pIII. Thus, using various suppressor and non-suppressor strainsof E. coli and with the addition of glucose, iso-propylthio-β-D-galactoside (IPTG) or a helper phage, such as VCS M13, thevector is able to replicate as a plasmid with no expression, producelarge quantities of the polypeptide library member only or productphage, some of which contain at least one copy of the polypeptide-pIIIfusion on their surface.

The libraries and repertoires of the disclosure can contain antibodyformats. For example, the polypeptide contained within the libraries andrepertoires can be whole antibodies or fragments thereof, such as Fab,F(ab′)2, Fv or scFv fragments, separate V_(H) or V_(L) domains, any ofwhich are either modified or unmodified. scFv fragments, as well asother antibody polypeptides, can be readily produced using any suitablemethod. A number of suitable antibody engineering methods are well knownin the art. example, a scFv can be formed by linking nucleic acidsencoding two variable domains with a suitable oligonucleotide thatencodes an appropriate linker peptide, such as (Gly- The linker bridgesthe C-terminal end of the first V region and the N-terminal end of thesecond V region. Similar techniques for the construction of otherantibody formats, such as Fv, Fab and F(ab′)2 fragments can be used. Toformat Fab and F(ab′)2 fragments, V_(H) and V_(L) polypeptides can becombined with constant region segments, which may be isolated fromrearranged genes, germline C genes or synthesized from antibody sequencedata. A library or repertoire according to the disclosure can be a V_(H)or V_(L) library or repertoire.

The polypeptides comprising a protease resistant variable domainpreferably comprise a target ligand binding site and/or a generic ligandbinding site. In certain embodiments, the generic ligand binding site isa binding site for a superantigen, such as protein A, protein L orprotein G. The variable domains can be based on any desired variabledomain, for example a human V_(H) (e.g., V_(H) 1a, V_(H) 1b, V_(H) 2,V_(H) 3, V_(H) 4, V_(H) 5, V_(H) 6), a human Vλ (e.g., VλI, VλII, VλIII,VλIV, VλV, VλVI, or Vκ1) or a human Vκ (e.g., Vκ2, Vκ3, Vκ4, Vκ5, Vκ6,Vκ7, Vκ8, Vκ9 or Vκ10).

Nucleic Acids, Host Cells and Methods for Producing Protease ResistantPolypeptides

The disclosure also relates to isolated and/or recombinant nucleic acidsencoding protease resistant peptides or polypeptides e.g., that areselectable or selected by the methods described herein.

Nucleic acids referred to herein as “isolated” are nucleic acids whichhave been separated away from other material (e.g., other nucleic acidssuch as genomic DNA, cDNA and/or RNA) in its original environment (e.g.,in cells or in a mixture of nucleic acids such as a library). Anisolated nucleic acid can be isolated as part of a vector (e.g., aplasmid).

Nucleic acids referred to herein as “recombinant” are nucleic acidswhich have been produced by recombinant DNA methodology, includingmethods which rely upon artificial recombination, such as cloning into avector or chromosome using, for example, restriction enzymes, homologousrecombination, viruses and the like, and nucleic acids prepared usingthe polymerase chain reaction (PCR).

The disclosure also relates to a recombinant host cell which comprises a(one or more) recombinant nucleic acid or expression constructcomprising a nucleic acid encoding a protease resistant peptide orpolypeptide, e.g., a peptide or polypeptide selectable or selected bythe methods described herein. The disclosure also includes a method ofpreparing a protease resistant peptide or polypeptide, comprisingmaintaining a recombinant host cell of the disclosure under conditionsappropriate for expression of a protease resistant peptide orpolypeptide. The method can further comprise the step of isolating orrecovering the protease resistant peptide or polypeptide, if desired.

For example, a nucleic acid molecule (i.e., one or more nucleic acidmolecules) encoding a protease resistant peptide or polypeptide, or anexpression construct (i.e., one or more constructs) comprising suchnucleic acid molecule(s), can be introduced into a suitable host cell tocreate a recombinant host cell using any method appropriate to the hostcell selected (e.g., transformation, transfection, electroporation,infection), such that the nucleic acid molecule(s) are operably linkedto one or more expression control elements (e.g., in a vector, in aconstruct created by processes in the cell, integrated into the hostcell genome). The resulting recombinant host cell can be maintainedunder conditions suitable for expression (e.g., in the presence of aninducer, in a suitable animal, in suitable culture media supplementedwith appropriate salts, growth factors, antibiotics, nutritionalsupplements, etc.), whereby the encoded peptide or polypeptide isproduced. If desired, the encoded peptide or polypeptide can be isolatedor recovered (e.g., from the animal, the host cell, medium, milk). Thisprocess encompasses expression in a host cell of a transgenic animal(see, e.g., WO 92/03918, GenPharm International).

The protease resistant peptide or polypeptide selected by the methoddescribed herein can also be produced in a suitable in vitro expressionsystem, by chemical synthesis or by any other suitable method.

Polypeptides, dAbs, Agonists, & Antagonists

As described and exemplified herein, protease resistant polypeptides,peptides or dAbs of the disclosure generally bind their target ligandwith high affinity. Thus, in another aspect, there is provided a methodfor selecting, isolating and/or recovering a polypeptide or dAb of thedisclosure that binds target antigen with high affinity. Generally, themethod comprises providing a library or repertoire of peptides orpolypeptides (eg dAbs), combining the library or repertoire with aprotease (e.g., trypsin, elastase, leucozyme, pancreatin, sputum) underconditions suitable for protease activity, and selecting, isolatingand/or recovering a peptide or polypeptide that binds a ligand (e.g.,target ligand). Because the library or repertoire has been exposed toprotease under conditions where protease sensitive peptides orpolypeptides will be digested, the activity of protease can eliminatethe less stable polypeptides that have low binding affinity, and therebyproduce a collection of high affinity binding peptides or polypeptides.For example, the polypeptide or dAb of the disclosure can bind targetantigen with an affinity (KD; KD=K_(off)(kd)/K_(on)(ka) as determined bysurface plasmon resonance) of 1 μM or stronger, or about 500 nM to about0.5 pM. For example, the polypeptide or dAb of the disclosure can bindtarget antigen (eg. TNFR1) with an affinity of about 500 nM, about 100nM, about 10 nM, about 1 nM, about 500 pM, about 100 pM, about 10 pM,about 1 pM or about 0.5 pM. Although we are not bound by any particulartheory, peptides and polypeptides that are resistant to proteases arebelieved to have a lower entropy and/or a higher stabilization energy.Thus, the correlation between protease resistance and high affinitybinding may be related to the compactness and stability of the surfacesof the peptides and polypeptides and dAbs selected by the methoddescribed herein.

The polypeptide, dAb, agonist or antagonist can be expressed in E. colior in Pichia species (e.g., P. pastoris). In one embodiment, the ligandor dAb monomer is secreted in a quantity of at least about 0.5 mg/L whenexpressed in E. coli or in Pichia species (e.g., P. pastoris). Although,the ligands and dAb monomers described herein can be secretable whenexpressed in E. coli or in Pichia species (e.g., P. pastoris), they canbe produced using any suitable method, such as synthetic chemicalmethods or biological production methods that do not employ E. coli orPichia species.

In some embodiments, the polypeptide, dAb, agonist or antagonist doesnot comprise a Camelid immunoglobulin variable domain, or one or moreframework amino acids that are unique to immunoglobulin variable domainsencoded by Camelid germline antibody gene segments, eg at position 108,37, 44, 45 and/or 47.

Agonists or antagonists according to the disclosure can be monovalent ormultivalent. In some embodiments, the agonist or antagonist ismonovalent and contains one binding site that interacts with targetantigen, the binding site provided by a polypeptide or dAb of thedisclosure. Monovalent agonists or antagonists bind one target antigenand may not induce cross-linking or clustering of target antigen (eg,receptor antigens) on the surface of cells which can lead to activationof the receptor and signal transduction.

In other embodiments, the agonist or antagonist of the disclosure ismultivalent. Multivalent agonists or antagonists can contain two or morecopies of a particular binding site for target antigen or contain two ormore different binding sites that bind target antigen, at least one ofthe binding sites being provided by a polypeptide or dAb of thedisclosure. For example, as described herein the agonist or antagonistcan be a dimer, trimer or multimer comprising two or more copies of aparticular polypeptide or dAb of the disclosure that binds targetantigen, or two or more different polypeptides or dAbs of the disclosurethat bind target antigen. In one embodiment, a multivalent antagonistbinds a cell surface receptor antigen and does not substantially agonizethe antigen (act as an agonist of the antigen) in a standard cell assay.

In certain embodiments, the multivalent agonist or antagonist containstwo or more binding sites for a desired epitope or domain of targetantigen.

In other embodiments, the polypeptide may be an insulinotropic agentsuch as a GLP-1 derived peptide. Suitable methods for determining thepotency of an insulinotropic agent, resistance to proteases such asDPP-IV, half life after administration and in vivo effects aredescribed, for example in WO 2006/059106.

In other embodiments, the multivalent agonist or antagonist contains twoor more binding sites provided by polypeptides or dAbs of the disclosurethat bind to different epitopes or domains of target antigen.

In certain embodiments, the polypeptide, dAb, agonist or antagonist ofthe disclosure are efficacious in models of chronic inflammatorydiseases when an effective amount is administered. Generally aneffective amount is about 1 mg/kg to about 10 mg/kg (e.g., about 1mg/kg, about 2 mg/kg, about 3 mg/kg, about 4 mg/kg, about 5 mg/kg, about6 mg/kg, about 7 mg/kg, about 8 mg/kg, about 9 mg/kg, or about 10mg/kg). The models of chronic inflammatory disease (see those describedin WO2006038027) are recognized by those skilled in the art as beingpredictive of therapeutic efficacy in humans.

Generally, the present ligands (e.g., agonists, antagonists) will beutilised in purified form together with pharmacologically appropriatecarriers. Typically, these carriers include aqueous or alcoholic/aqueoussolutions, emulsions or suspensions, any including saline and/orbuffered media. Parenteral vehicles include sodium chloride solution,Ringer's dextrose, dextrose and sodium chloride and lactated Ringer's.Suitable physiologically-acceptable adjuvants, if necessary to keep apolypeptide complex in suspension, may be chosen from thickeners such ascarboxymethylcellulose, polyvinylpyrrolidone, gelatin and alginates.

Intravenous vehicles include fluid and nutrient replenishers andelectrolyte replenishers, such as those based on Ringer's dextrose.Preservatives and other additives, such as antimicrobials, antioxidants,chelating agents and inert gases, may also be present (Mack (1982)Remington's Pharmaceutical Sciences, 16th Edition). A variety ofsuitable formulations can be used, including extended releaseformulations.

The ligands (e.g., antagonists) of the present disclosure may be used asseparately administered compositions or in conjunction with otheragents. These can include various immunotherapeutic drugs, such ascylcosporine, methotrexate, adriamycin or cisplatinum, and immunotoxins.Pharmaceutical compositions can include “cocktails” of various cytotoxicor other agents in conjunction with the ligands of the presentdisclosure, or even combinations of ligands according to the presentdisclosure having different specificities, such as ligands selectedusing different target antigens or epitopes, whether or not they arepooled prior to administration.

The route of administration of pharmaceutical compositions according tothe disclosure may be any of those commonly known to those of ordinaryskill in the art. For therapy, including without limitationimmunotherapy, the selected ligands thereof of the disclosure can beadministered to any patient in accordance with standard techniques.

The administration can be by any appropriate mode, includingparenterally, intravenously, intramuscularly, intraperitoneally,transdermally, via the pulmonary route, or also, appropriately, bydirect infusion with a catheter. The dosage and frequency ofadministration will depend on the age, sex and condition of the patient,concurrent administration of other drugs, counterindications and otherparameters to be taken into account by the clinician. Administration canbe local (e.g., local delivery to the lung by pulmonary administration,e.g., intranasal administration) or systemic as indicated.

The ligands of this disclosure can be lyophilised for storage andreconstituted in a suitable carrier prior to use. This technique hasbeen shown to be effective with conventional immunoglobulins andart-known lyophilisation and reconstitution techniques can be employed.It will be appreciated by those skilled in the art that lyophilisationand reconstitution can lead to varying degrees of antibody activity loss(e.g. with conventional immunoglobulins, IgM antibodies tend to havegreater activity loss than IgG antibodies) and that use levels may haveto be adjusted upward to compensate.

The compositions containing the present ligands (e.g., agonists,antagonists) or a cocktail thereof can be administered for prophylacticand/or therapeutic treatments. In certain therapeutic applications, anadequate amount to accomplish at least partial inhibition, suppression,modulation, killing, or some other measurable parameter, of a populationof selected cells is defined as a “therapeutically-effective dose”.Amounts needed to achieve this dosage will depend upon the severity ofthe disease and the general state of the patient's own immune system,but generally range from 0.005 to 5.0 mg of ligand, e.g. dAb, agonist orantagonist per kilogram of body weight, with doses of 0.05 to 2.0mg/kg/dose being more commonly used. For prophylactic applications,compositions containing the present ligands or cocktails thereof mayalso be administered in similar or slightly lower dosages, to prevent,inhibit or delay onset of disease (e.g., to sustain remission orquiescence, or to prevent acute phase). The skilled clinician will beable to determine the appropriate dosing interval to treat, suppress orprevent disease. Treatment or therapy performed using the compositionsdescribed herein is considered “effective” if one or more symptoms arereduced (e.g., by at least 10% or at least one point on a clinicalassessment scale), relative to such symptoms present before treatment,or relative to such symptoms in an individual (human or model animal)not treated with such composition or other suitable control. Symptomswill obviously vary depending upon the disease or disorder targeted, butcan be measured by an ordinarily skilled clinician or technician. Suchsymptoms can be measured, for example, by monitoring the level of one ormore biochemical indicators of the disease or disorder (e.g., levels ofan enzyme or metabolite correlated with the disease, affected cellnumbers, etc.), by monitoring physical manifestations (e.g.,inflammation, tumor size, etc.), or by an accepted clinical assessmentscale, for example, the Expanded Disability Status Scale (for multiplesclerosis), the Irvine Inflammatory Bowel Disease Questionnaire (32point assessment evaluates quality of life with respect to bowelfunction, systemic symptoms, social function and emotional status—scoreranges from 32 to 224, with higher scores indicating a better quality oflife), the Quality of Life Rheumatoid Arthritis Scale, or other acceptedclinical assessment scale as known in the field. A sustained (e.g., oneday or more, or longer) reduction in disease or disorder symptoms by atleast 10% or by one or more points on a given clinical scale isindicative of “effective” treatment. Similarly, prophylaxis performedusing a composition as described herein is “effective” if the onset orseverity of one or more symptoms is delayed, reduced or abolishedrelative to such symptoms in a similar individual (human or animalmodel) not treated with the composition.

A composition containing a ligand (e.g., agonist, antagonist) orcocktail thereof according to the present disclosure may be utilised inprophylactic and therapeutic settings to aid in the alteration,inactivation, killing or removal of a select target cell population in amammal. In addition, the selected repertoires of polypeptides describedherein may be used extracorporeally or in vitro selectively to kill,deplete or otherwise effectively remove a target cell population from aheterogeneous collection of cells. Blood from a mammal may be combinedextracorporeally with the ligands whereby the undesired cells are killedor otherwise removed from the blood for return to the mammal inaccordance with standard techniques.

A composition containing a ligand (e.g., agonist or antagonist)according to the present disclosure may be utilised in prophylactic andtherapeutic settings to aid in the alteration, inactivation, killing orremoval of a select target cell population in a mammal.

The ligands (e.g., anti-target antigen antagonists, agonists, dAbmonomers) can be administered and or formulated together with one ormore additional therapeutic or active agents. When a ligand (eg, a dAb)is administered with an additional therapeutic agent, the ligand can beadministered before, simultaneously with or subsequent to administrationof the additional agent. Generally, the ligand and additional agent areadministered in a manner that provides an overlap of therapeutic effect.

In a preferred embodiment of the disclosure pharmaceutical compositionscontaining a GLP-1 drug or GLP-1 analogue or derivative according to thepresent disclosure may be administered parenterally to patients in needof such a treatment. Parenteral administration may be performed bysubcutaneous, intramuscular or intravenous injection by means of asyringe, optionally a pen-like syringe. Alternatively, parenteraladministration can be performed by means of an infusion pump. A furtheroption is a composition which may be a powder or a liquid for theadministration of the GLP-1 drug or GLP-1 analogue or derivative in theform of a nasal or pulmonal spray. As a still further option, the GLP-1drug or GLP-1 analogue or derivative of the disclosure can also beadministered transdermally, e. g. from a patch, optionally aniontophoretic patch, or transmucosally, e. g. bucally. In otherembodiments the compositions are administered orally, eg as a pill,capsule, drink (eg, marketed as a weight-loss drink for obesitytreatment).

A composition for parenteral administration of GLP-1 compounds may, forexample, be prepared as described in WO 03/002136 (incorporated hereinby reference).

In another embodiment the present disclosure relates to the use of acompound according to the disclosure for the preparation of a medicamentfor the treatment of hyperglycemia, type 1 diabetes, type 2 diabetes orB-cell deficiency. In specific embodiments for these indications, thedrug is selected from an insulinotropic agent, and incretin, aglucagon-like 1 peptide, a GLP-1 peptide, a GLP-1 analogue, a GLP-1derivative, PYY, a PYY peptide, a PYY analogue, a PYY derivative,Exendin-3, an Exendin-3 peptide, an Exendin-3 analogue, an Exendin-3derivative, Exendin-4, an Exendin-4 peptide, an Exendin-4 analogue, anExendin-4 derivative or a combination of two or more of these (eg, GLP-1peptide and a PYY peptide).

The treatment with a compound according to the present disclosure mayalso be combined with a second or more pharmacologically activesubstances which may or may not be part of the drug conjugate or fusion.For example, an active selected from antidiabetic agents, antiobesityagents, appetite regulating agents, antihypertensive agents, agents forthe treatment and/or prevention of complications resulting from orassociated with diabetes and agents for the treatment and/or preventionof complications and disorders resulting from or associated withobesity. In the present context the expression “antidiabetic agent”includes compounds for the treatment and/or prophylaxis of insulinresistance and diseases wherein insulin resistance is thepathophysiological mechanism.

Formats

Increased half-life is useful in in vivo applications ofimmunoglobulins, especially antibodies and most especially antibodyfragments of small size. Such fragments (Fvs, disulphide bonded Fvs,Fabs, scFvs, dAbs) suffer from rapid clearance from the body; thus,whilst they are able to reach most parts of the body rapidly, and arequick to produce and easier to handle, their in vivo applications havebeen limited by their only brief persistence in vivo. One embodiment ofthe disclosure solves this problem by providing increased half-life ofthe ligands in vivo and consequently longer persistence times in thebody of the functional activity of the ligand.

Methods for pharmacokinetic analysis and determination of ligandhalf-life will be familiar to those skilled in the art. Details may befound in Kenneth, A et al: Chemical Stability of Pharmaceuticals: AHandbook for Pharmacists and in Peters et al, Pharmacokinetc analysis: APractical Approach (1996). Reference is also made to “Pharmacokinetics”,M Gibaldi & D Perron, published by Marcel Dekker, 2^(nd) Rev. ex edition(1982), which describes pharmacokinetic parameters such as t alpha and tbeta half lives and area under the curve (AUC).

Half lives (t½ alpha and t½ beta) and AUC can be determined from a curveof serum concentration of ligand against time. The WinNonlin analysispackage (available from Pharsight Corp., Mountain View, Calif. 94040,USA) can be used, for example, to model the curve. In a first phase (thealpha phase) the ligand is undergoing mainly distribution in thepatient, with some elimination. A second phase (beta phase) is theterminal phase when the ligand has been distributed and the serumconcentration is decreasing as the ligand is cleared from the patient.The t alpha half life is the half life of the first phase and the t betahalf life is the half life of the second phase. Thus, in one embodiment,the present disclosure provides a ligand or a composition comprising aligand according to the disclosure having a tα half-life in the range of15 minutes or more. In one embodiment, the lower end of the range is 30minutes, 45 minutes, 1 hour, 2 hours, 3 hours, 4 hours, 5 hours, 6hours, 7 hours, 10 hours, 11 hours or 12 hours. In addition, oralternatively, a ligand or composition according to the disclosure willhave a tα half life in the range of up to and including 12 hours. In oneembodiment, the upper end of the range is 11, 10, 9, 8, 7, 6 or 5 hours.An example of a suitable range is 1 to 6 hours, 2 to 5 hours or 3 to 4hours.

In one embodiment, the present disclosure provides a ligand(polypeptide, dAb, agonist or antagonist) or a composition comprising aligand according to the disclosure having a tβ half-life in the range of2.5 hours or more. In one embodiment, the lower end of the range is 3hours, 4 hours, 5 hours, 6 hours, 7 hours, 10 hours, 11 hours, or 12hours. In addition, or alternatively, a ligand or composition accordingto the disclosure has a tβ half-life in the range of up to and including21 days. In one embodiment, the upper end of the range is 12 hours, 24hours, 2 days, 3 days, 5 days, 10 days, 15 days or 20 days. In oneembodiment a ligand or composition according to the disclosure will havea tβ half life in the range 12 to 60 hours. In a further embodiment, itwill be in the range 12 to 48 hours. In a further embodiment still, itwill be in the range 12 to 26 hours.

In addition, or alternatively to the above criteria, the presentdisclosure provides a ligand or a composition comprising a ligandaccording to the disclosure having an AUC value (area under the curve)in the range of 1 mg·min/ml or more. In one embodiment, the lower end ofthe range is 5, 10, 15, 20, 30, 100, 200 or 300 mg·min/ml. In addition,or alternatively, a ligand or composition according to the disclosurehas an AUC in the range of up to 600 mg·min/ml. In one embodiment, theupper end of the range is 500, 400, 300, 200, 150, 100, 75 or 50mg·min/ml. In one embodiment a ligand according to the disclosure willhave a AUC in the range selected from the group consisting of thefollowing: 15 to 150 mg·min/ml, 15 to 100 mg·min/ml, 15 to 75 mg·min/ml,and 15 to 50 mg·min/ml.

Polypeptides and dAbs of the disclosure and agonists or antagonistscomprising these can be formatted to have a larger hydrodynamic size,for example, by attachment of a PEG group, serum albumin, transferrin,transferrin receptor or at least the transferrin-binding portionthereof, an antibody Fc region, or by conjugation to an antibody domain.For example, polypeptides dAbs, agonists and antagonists formatted as alarger antigen-binding fragment of an antibody or as an antibody (e.g.,formatted as a Fab, Fab′, F(ab)₂, F(ab′)2, IgG, scFv).

Hydrodynamic size of the ligands (e.g., dAb monomers and multimers) ofthe in disclosure vention may be determined using methods which are wellknown in the art. For example, gel filtration chromatography may be usedto determine the hydrodynamic size of a ligand. Suitable gel filtrationmatrices for determining the hydrodynamic sizes of ligands, such ascross-linked agarose matrices, are well known and readily available.

The size of a ligand format (e.g., the size of a PEG moiety attached toa dAb monomer), can be varied depending on the desired application. Forexample, where ligand is intended to leave the circulation and enterinto peripheral tissues, it is desirable to keep the hydrodynamic sizeof the ligand low to facilitate extravazation from the blood stream.Alternatively, where it is desired to have the ligand remain in thesystemic circulation for a longer period of time the size of the ligandcan be increased, for example by formatting as an Ig like protein.

Half-Life Extension by Targeting an Antigen or Epitope that IncreasesHalf-Live In Vivo

The hydrodynaminc size of a ligand and its serum half-life can also beincreased by conjugating or associating a target antigen bindingpolypeptide, dAb, agonist or antagonist of the disclosure to a bindingdomain (e.g., antibody or antibody fragment) that binds an antigen orepitope that increases half-live in vivo, as described herein. Forexample, the target antigen binding agent (e.g., polypeptide) can beconjugated or linked to an anti-serum albumin or anti-neonatal Fcreceptor antibody or antibody fragment, eg an anti-SA or anti-neonatalFc receptor dAb, Fab, Fab′ or scFv, or to an anti-SA affibody oranti-neonatal Fc receptor Affibody or an anti-SA avimer, or an anti-SAbinding domain which comprises a scaffold selected from, but preferablynot limited to, the group consisting of CTLA-4, lipocallin, SpA, anaffibody, an avimer, GroEl and fibronectin (see PCT/GB2008/000453 filed8 Feb. 2008 for disclosure of these binding domain, which domains andtheir sequences are incorporated herein by reference and form part ofthe disclosure of the present text). Conjugating refers to a compositioncomprising polypeptide, dAb, agonist or antagonist of the disclosurethat is bonded (covalently or noncovalently) to a binding domain thatbinds serum albumin.

Suitable polypeptides that enhance serum half-life in vivo include, forexample, transferrin receptor specific ligand-neuropharmaceutical agentfusion proteins (see U.S. Pat. No. 5,977,307, the teachings of which areincorporated herein by reference), brain capillary endothelial cellreceptor, transferrin, transferrin receptor (e.g., soluble transferrinreceptor), insulin, insulin-like growth factor 1 (IGF 1) receptor,insulin-like growth factor 2 (IGF 2) receptor, insulin receptor, bloodcoagulation factor X, α1-antitrypsin and HNF 1α. Suitable polypeptidesthat enhance serum half-life also include alpha-1 glycoprotein(orosomucoid; AAG), alpha-1 antichymotrypsin (ACT), alpha-1microglobulin (protein HC; AIM), antithrombin III (AT III),apolipoprotein A-1 (Apo A-1), apolipoprotein B (Apo B), ceruloplasmin(Cp), complement component C3 (C3), complement component C4 (C4), C1esterase inhibitor (C1 INH), C-reactive protein (CRP), ferritin (FER),hemopexin (HPX), lipoprotein(a) (Lp(a)), mannose-binding protein (MBP),myoglobin (Myo), prealbumin (transthyretin; PAL), retinol-bindingprotein (RBP), and rheumatoid factor (RF).

Suitable proteins from the extracellular matrix include, for example,collagens, laminins, integrins and fibronectin. Collagens are the majorproteins of the extracellular matrix. About 15 types of collagenmolecules are currently known, found in different parts of the body,e.g. type I collagen (accounting for 90% of body collagen) found inbone, skin, tendon, ligaments, cornea, internal organs or type IIcollagen found in cartilage, vertebral disc, notochord, and vitreoushumor of the eye.

Suitable proteins from the blood include, for example, plasma proteins(e.g., fibrin, α-2 macroglobulin, serum albumin, fibrinogen (e.g.,fibrinogen A, fibrinogen B), serum amyloid protein A, haptoglobin,profilin, ubiquitin, uteroglobulin and β-2-microglobulin), enzymes andenzyme inhibitors (e.g., plasminogen, lysozyme, cystatin C,alpha-1-antitrypsin and pancreatic trypsin inhibitor), proteins of theimmune system, such as immunoglobulin proteins (e.g., IgA, IgD, IgE,IgG, IgM, immunoglobulin light chains (kappa/lambda)), transportproteins (e.g., retinol binding protein, α-1 microglobulin), defensins(e.g., beta-defensin 1, neutrophil defensin 1, neutrophil defensin 2 andneutrophil defensin 3) and the like.

Suitable proteins found at the blood brain barrier or in neural tissueinclude, for example, melanocortin receptor, myelin, ascorbatetransporter and the like.

Suitable polypeptides that enhance serum half-life in vivo also includeproteins localized to the kidney (e.g., polycystin, type IV collagen,organic anion transporter Kl, Heymann's antigen), proteins localized tothe liver (e.g., alcohol dehydrogenase, G250), proteins localized to thelung (e.g., secretory component, which binds IgA), proteins localized tothe heart (e.g., HSP 27, which is associated with dilatedcardiomyopathy), proteins localized to the skin (e.g., keratin), bonespecific proteins such as morphogenic proteins (BMPs), which are asubset of the transforming growth factor superfamily of proteins thatdemonstrate osteogenic activity (e.g., BMP-2, BMP-4, BMP-5, BMP-6,BMP-7, BMP-8), tumor specific proteins (e.g., trophoblast antigen,herceptin receptor, oestrogen receptor, cathepsins (e.g., cathepsin B,which can be found in liver and spleen)).

Suitable disease-specific proteins include, for example, antigensexpressed only on activated T-cells, including LAG-3 (lymphocyteactivation gene), osteoprotegerin ligand (OPGL; see Nature 402, 304-309(1999)), OX40 (a member of the TNF receptor family, expressed onactivated T cells and specifically up-regulated in human T cell leukemiavirus type-I (HTLV-I)-producing cells; see Immunol. 165 (1):263-70(2000)). Suitable disease-specific proteins also include, for example,metalloproteases (associated with arthritis/cancers) including CG6512Drosophila, human paraplegin, human FtsH, human AFG3L2, murine ftsH; andangiogenic growth factors, including acidic fibroblast growth factor(FGF-1), basic fibroblast growth factor (FGF-2), vascular endothelialgrowth factor/vascular permeability factor (VEGF/VPF), transforminggrowth factor-α (TGF α), tumor necrosis factor-alpha (TNF-α),angiogenin, interleukin-3 (IL-3), interleukin-8 (IL-8), platelet-derivedendothelial growth factor (PD-ECGF), placental growth factor (P1GF),midkine platelet-derived growth factor-BB (PDGF), and fractalkine.

Suitable polypeptides that enhance serum half-life in vivo also includestress proteins such as heat shock proteins (HSPs). HSPs are normallyfound intracellularly. When they are found extracellularly, it is anindicator that a cell has died and spilled out its contents. Thisunprogrammed cell death (necrosis) occurs when as a result of trauma,disease or injury, extracellular HSPs trigger a response from the immunesystem. Binding to extracellular HSP can result in localizing thecompositions of the disclosure to a disease site.

Suitable proteins involved in Fc transport include, for example,Brambell receptor (also known as FcRB). This Fc receptor has twofunctions, both of which are potentially useful for delivery. Thefunctions are (1) transport of IgG from mother to child across theplacenta (2) protection of IgG from degradation thereby prolonging itsserum half-life. It is thought that the receptor recycles IgG fromendosomes. (See, Holliger et al, Nat Biotechnol 15(7):632-6 (1997).)

dAbs that Bind Serum Albumin (ALBUDABs™)

The disclosure in one embodiment provides a polypeptide, agonist orantagonist (e.g., dual specific ligand comprising an anti-target antigendAb (a first dAb)) that binds to target antigen and a second dAb thatbinds serum albumin (SA), the second dAb binding SA with a K_(D) asdetermined by surface plasmon resonance of 1 nM to 1, 2, 3, 4, 5, 10,20, 30, 40, 50, 60, 70, 100, 200, 300, 400 or 500 μM (i.e., ×10⁻⁹ to5×10⁻⁴), or 100 nM to 10 μM, or 1 to 5 μM or 3 to 70 nM or 10 nM to 1,2, 3, 4 or 5 μM. For example 30 to 70 nM as determined by surfaceplasmon resonance. In one embodiment, the first dAb (or a dAb monomer)binds SA (e.g., HSA) with a K_(D) as determined by surface plasmonresonance of approximately 1, 50, 70, 100, 150, 200, 300 nM or 1, 2 or 3μM. In one embodiment, for a dual specific ligand comprising a firstanti-SA dAb and a second dAb to target antigen, the affinity (eg K_(D)and/or K_(off) as measured by surface plasmon resonance, eg usingBIACORE™) of the second dAb for its target is from 1 to 100000 times(eg, 100 to 100000, or 1000 to 100000, or 10000 to 100000 times) theaffinity of the first dAb for SA. In one embodiment, the serum albuminis human serum albumin (HSA). For example, the first dAb binds SA withan affinity of approximately 10 μM, while the second dAb binds itstarget with an affinity of 100 pM. In one embodiment, the serum albuminis human serum albumin (HSA). In one embodiment, the first dAb binds SA(eg, HSA) with a K_(D) of approximately 50, for example 70, 100, 150 or200 nM. Details of dual specific ligands are found in WO03002609,WO04003019 and WO04058821.

The ligands of the disclosure can in one embodiment comprise a dAb thatbinds serum albumin (SA) with a K_(D) as determined by surface plasmonresonance of 1 nM to 1, 2, 3, 4, 5, 10, 20, 30, 40, 50, 60, 70, 100,200, 300, 400 or 500 μM (i.e., ×10⁻⁹ to 5×10⁻⁴), or 100 nM to 10 μM, or1 to 5 μM or 3 to 70 nM or 10 nM to 1, 2, 3, 4 or 5μ M. For example 30to 70 nM as determined by surface plasmon resonance. In one embodiment,the first dAb (or a dAb monomer) binds SA (e.g., HSA) with a K_(D) asdetermined by surface plasmon resonance of approximately 1, 50, 70, 100,150, 200, 300 nM or 1, 2 or 3 μM. In one embodiment, the first andsecond dAbs are linked by a linker, for example a linker of from 1 to 4amino acids or from 1 to 3 amino acids, or greater than 3 amino acids orgreater than 4, 5, 6, 7, 8, 9, 10, 15 or 20 amino acids. In oneembodiment, a longer linker (greater than 3 amino acids) is used toenhance potency (K_(D) of one or both dAbs in the agonist orantagonist). In one embodiment, the linker is a helical linker.

In particular embodiments of the ligands, agonists and antagonists, thedAb binds human serum albumin and competes for binding to albumin with adAb selected from the group consisting of

MSA-16, MSA-26 (See WO04003019 for disclosure of these sequences, whichsequences and their nucleic acid counterpart are incorporated herein byreference and form part of the disclosure of the present text),

DOM7m-16 (SEQ ID NO: 473), DOM7m-12 (SEQ ID NO: 474), DOM7m-26 (SEQ IDNO: 475), DOM7r-1 (SEQ ID NO: 476), DOM7r-3 (SEQ ID NO: 477), DOM7r-4(SEQ ID NO: 478), DOM7r-5 (SEQ ID NO: 479), DOM7r-7 (SEQ ID NO: 480),DOM7r-8 (SEQ ID NO: 481), DOM7h-2 (SEQ ID NO: 482), DOM7h-3 (SEQ ID NO:483), DOM7h-4 (SEQ ID NO: 484), DOM7h-6 (SEQ ID NO: 485), DOM7h-1 (SEQID NO: 486), DOM7h-7 (SEQ ID NO: 487), DOM7h-22 (SEQ ID NO: 489),DOM7h-23 (SEQ ID NO: 490), DOM7h-24 (SEQ ID NO: 491), DOM7h-25 (SEQ IDNO: 492), DOM7h-26 (SEQ ID NO: 493), DOM7h-21 (SEQ ID NO: 494), DOM7h-27(SEQ ID NO: 495), DOM7h-8 (SEQ ID NO: 496), DOM7r-13 (SEQ ID NO: 497),DOM7r-14 (SEQ ID NO: 498), DOM7r-15 (SEQ ID NO: 499), DOM7r-16 (SEQ IDNO: 500), DOM7r-17 (SEQ ID NO: 501), DOM7r-18 (SEQ ID NO: 502), DOM7r-19(SEQ ID NO: 503), DOM7r-20 (SEQ ID NO: 504), DOM7r-21 (SEQ ID NO: 505),DOM7r-22 (SEQ ID NO: 506), DOM7r-23 (SEQ ID NO: 507), DOM7r-24 (SEQ IDNO: 508), DOM7r-25 (SEQ ID NO: 509), DOM7r-26 (SEQ ID NO: 510), DOM7r-27(SEQ ID NO: 511), DOM7r-28 (SEQ ID NO: 512), DOM7r-29 (SEQ ID NO: 513),DOM7r-30 (SEQ ID NO: 514), DOM7r-31 (SEQ ID NO: 515), DOM7r-32 (SEQ IDNO: 516), DOM7r-33 (SEQ ID NO: 517) (See WO2007080392 for disclosure ofthese sequences, which sequences and their nucleic acid counterpart areincorporated herein by reference and form part of the disclosure of thepresent text; the SEQ ID No's in this paragraph are those that appear inWO2007080392),

dAb8 (dAb10), dAb 10, dAb36, dAb7r20 (DOM7r20), dAb7r21 (DOM7r21),dAb7r22 (DOM7r22), dAb7r23 (DOM7r23), dAb7r24 (DOM7r24), dAb7r25(DOM7r25), dAb7r26 (DOM7r26), dAb7r27 (DOM7r27), dAb7r28 (DOM7r28),dAb7r29 (DOM7r29), dAb7r29 (DOM7r29), dAb7r31 (DOM7r31), dAb7r32(DOM7r32), dAb7r33 (DOM7r33), dAb7r33 (DOM7r33), dAb7h22 (DOM7h22),dAb7h23 (DOM7h23), dAb7h24 (DOM7h24), dAb7h25 (DOM7h25), dAb7h26(DOM7h26), dAb7h27 (DOM7h27), dAb7h30 (DOM7h30), dAb7h31 (DOM7h31), dAb2(dAbs 4,7,41), dAb4, dAb7, dAb11, dAb 12 (dAb7m12), dAb 13 (dAb 15),dAb15, dAb 16 (dAb21, dAb7m16), dAb17, dAb18, dAb19, dAb21, dAb22,dAb23, dAb24, dAb25 (dAb26, dAb7m26), dAb27, dAb30 (dAb35), dAb31,dAb33, dAb34, dAb35, dAb38 (dAb54), dAb41, dAb46 (dAbs 47, 52 and 56),dAb47, dAb52, dAb53, dAb54, dAb55, dAb56, dAb7m12, dAb7m16, dAb7m26,dAb7r1 (DOM 7r1), dAb7r3 (DOM7r3), dAb7r4 (DOM7r4), dAb7r5 (DOM7r5),dAb7r7 (DOM7r7), dAb7r8 (DOM7r8), dAb7r13 (DOM7r13), dAb7r14 (DOM7r14),dAb7r15 (DOM7r15), dAb7r16 (DOM7r16), dAb7r17 (DOM7r17), dAb7r18(DOM7r18), dAb7r19 (DOM7r19), dAb7h1 (DOM7h1), dAb7h2 (DOM7h2), dAb7h6(DOM7h6), dAb7h7 (DOM7h7), dAb7h8 (DOM7h8), dAb7h9 (DOM7h9), dAb7h10(DOM7h10), dAb7h11 (DOM7h11), dAb7h12 (DOM7h12), dAb7h13 (DOM7h13),dAb7h14 (DOM7h14), dAb7p1 (DOM7p1), and dAb7p2 (DOM7p2) (seeWO2008096158 for disclosure of these sequences, which sequences andtheir nucleic acid counterpart are incorporated herein by reference andform part of the disclosure of the present text). Alternative names areshown in brackets after the dAb, e.g. dAb8 has an alternative name whichis dAb 10 i.e. dAb 8 (dAb 10).

In certain embodiments, the dAb binds human serum albumin and comprisesan amino acid sequence that has at least about 80%, or at least about85%, or at least about 90%, or at least about 95%, or at least about96%, or at least about 97%, or at least about 98%, or at least about 99%amino acid sequence identity with the amino acid sequence of a dAbselected from the group consisting of

MSA-16, MSA-26,

DOM7m-16 (SEQ ID NO: 473), DOM7m-12 (SEQ ID NO: 474), DOM7m-26 (SEQ IDNO: 475), DOM7r-1 (SEQ ID NO: 476), DOM7r-3 (SEQ ID NO: 477), DOM7r-4(SEQ ID NO: 478), DOM7r-5 (SEQ ID NO: 479), DOM7r-7 (SEQ ID NO: 480),DOM7r-8 (SEQ ID NO: 481), DOM7h-2 (SEQ ID NO: 482), DOM7h-3 (SEQ ID NO:483), DOM7h-4 (SEQ ID NO: 484), DOM7h-6 (SEQ ID NO: 485), DOM7h-1 (SEQID NO: 486), DOM7h-7 (SEQ ID NO: 487), DOM7h-22 (SEQ ID NO: 489),DOM7h-23 (SEQ ID NO: 490), DOM7h-24 (SEQ ID NO: 491), DOM7h-25 (SEQ IDNO: 492), DOM7h-26 (SEQ ID NO: 493), DOM7h-21 (SEQ ID NO: 494), DOM7h-27(SEQ ID NO: 495), DOM7h-8 (SEQ ID NO: 496), DOM7r-13 (SEQ ID NO: 497),DOM7r-14 (SEQ ID NO: 498), DOM7r-15 (SEQ ID NO: 499), DOM7r-16 (SEQ IDNO: 500), DOM7r-17 (SEQ ID NO: 501), DOM7r-18 (SEQ ID NO: 502), DOM7r-19(SEQ ID NO: 503), DOM7r-20 (SEQ ID NO: 504), DOM7r-21 (SEQ ID NO: 505),DOM7r-22 (SEQ ID NO: 506), DOM7r-23 (SEQ ID NO: 507), DOM7r-24 (SEQ IDNO: 508), DOM7r-25 (SEQ ID NO: 509), DOM7r-26 (SEQ ID NO: 510), DOM7r-27(SEQ ID NO: 511), DOM7r-28 (SEQ ID NO: 512), DOM7r-29 (SEQ ID NO: 513),DOM7r-30 (SEQ ID NO: 514), DOM7r-31 (SEQ ID NO: 515), DOM7r-32 (SEQ IDNO: 516), DOM7r-33 (SEQ ID NO: 517) (the SEQ ID No's in this paragraphare those that appear in WO2007080392),

dAb8, dAb 10, dAb36, dAb7r20, dAb7r21, dAb7r22, dAb7r23, dAb7r24,dAb7r25, dAb7r26, dAb7r27, dAb7r28, dAb7r29, dAb7r30, dAb7r31, dAb7r32,dAb7r33, dAb7h21, dAb7h22, dAb7h23, Ab7h24, Ab7h25, Ab7h26, dAb7h27,dAb7h30, dAb7h31, dAb2, dAb4, dAb7, dAb11, dAb12, dAb13, dAb15, dAb16,dAb17, dAb18, dAb19, dAb21, dAb22, dAb23, dAb24, dAb25, dAb26, dAb27,dAb30, dAb31, dAb33, dAb34, dAb35, dAb38, dAb41, dAb46, dAb47, dAb52,dAb53, dAb54, dAb55, dAb56, dAb7m12, dAb7m16, dAb7m26, dAb7r1, dAb7r3,dAb7r4, dAb7r5, dAb7r7, dAb7r8, dAb7r13, dAb7r14, dAb7r15, dAb7r16,dAb7r17, dAb7r18, dAb7r19, dAb7h1, dAb7h2, dAb7h6, dAb7h7, dAb7h8,dAb7h9, dAb7h10, dAb7h11, dAb7h12, dAb7h13, dAb7h14, dAb7p1, and dAb7p2.

For example, the dAb that binds human serum albumin can comprise anamino acid sequence that has at least about 90%, or at least about 95%,or at least about 96%, or at least about 97%, or at least about 98%, orat least about 99% amino acid sequence identity with DOM7h-2 (SEQ IDNO:482), DOM7h-3 (SEQ ID NO:483), DOM7h-4 (SEQ ID NO:484), DOM7h-6 (SEQID NO:485), DOM7h-1 (SEQ ID NO:486), DOM7h-7 (SEQ ID NO:487), DOM7h-8(SEQ ID NO:496), DOM7r-13 (SEQ ID NO:497), DOM7r-14 (SEQ ID NO:498),DOM7h-22 (SEQ ID NO:489), DOM7h-23 (SEQ ID NO:490), DOM7h-24 (SEQ IDNO:491), DOM7h-25 (SEQ ID NO:492), DOM7h-26 (SEQ ID NO:493), DOM7h-21(SEQ ID NO:494), DOM7h-27 (SEQ ID NO:495) (the SEQ ID No's in thisparagraph are those that appear in WO2007080392), dAb8, dAb 10, dAb36,dAb7h21, dAb7h22, dAb7h23, Ab7h24, Ab7h25, Ab7h26, dAb7h27, dAb7h30,dAb7h31, dAb2, dAb4, dAb7, dAb11, dAb12, dAb13, dAb15, dAb16, dAb17,dAb18, dAb19, dAb21, dAb22, dAb23, dAb24, dAb25, dAb26, dAb27, dAb30,dAb31, dAb33, dAb34, dAb35, dAb38, dAb41, dAb46, dAb47, dAb52, dAb53,dAb54, dAb55, dAb56, dAb7h1, dAb7h2, dAb7h6, dAb7h7, dAb7h8, dAb7h9,dAb7h10, dAb7h11, dAb7h12, dAb7h13 and dAb7h14.

In certain embodiments, the dAb binds human serum albumin and comprisesan amino acid sequence that has at least about 80%, or at least about85%, or at least about 90%, or at least about 95%, or at least about96%, or at least about 97%, or at least about 98%, or at least about 99%amino acid sequence identity with the amino acid sequence of a dAbselected from the group consisting of

DOM7h-2 (SEQ ID NO:482), DOM7h-6 (SEQ ID NO:485), DOM7h-1 (SEQ IDNO:486), DOM7h-7 (SEQ ID NO:487), DOM7h-8 (SEQ ID NO:496), DOM7h-22 (SEQID NO:489), DOM7h-23 (SEQ ID NO:490), DOM7h-24 (SEQ ID NO:491), DOM7h-25(SEQ ID NO:492), DOM7h-26 (SEQ ID NO:493), DOM7h-21 (SEQ ID NO:494),DOM7h-27 (SEQ ID NO:495) (the SEQ ID No's in this paragraph are thosethat appear in WO2007080392),

dAb7h21, dAb7h22, dAb7h23, Ab7h24, Ab7h25, Ab7h26, dAb7h27, dAb7h30,dAb7h31, dAb2, dAb4, dAb7, dAb38, dAb41, dAb7h1, dAb7h2, dAb7h6, dAb7h7,dAb7h8, dAb7h9, dAb7h10, dAb7h11, dAb7h12, dAb7h13 and dAb7h14.

In more particular embodiments, the dAb is a V_(κ) dAb that binds humanserum albumin and has an amino acid sequence selected from the groupconsisting of

DOM7h-2 (SEQ ID NO:482), DOM7h-6 (SEQ ID NO:485), DOM7h-1 (SEQ IDNO:486), DOM7h-7 (SEQ ID NO:487), DOM7h-8 (SEQ ID NO:496) (the SEQ IDNo's in this paragraph are those that appear in WO2007080392),

dAb2, dAb4, dAb7, dAb38, dAb41, dAb54, dAb7h1, dAb7h2, dAb7h6, dAb7h7,dAb7h8, dAb7h9, dAb7h10, dAb7h11, dAb7h12, dAb7h13 and dAb7h14.

In more particular embodiments, the dAb is a V_(H) dAb that binds humanserum albumin and has an amino acid sequence selected from dAb7h30 anddAb7h31.

In more particular embodiments, the dAb is dAb7h11 or dAb7h14.

In other embodiments, the dAb, ligand, agonist or antagonist binds humanserum albumin and comprises one, two or three of the CDRs of any of theforegoing amino acid sequences, eg one, two or three of the CDRs ofdAb7h11 or dAb7h14.

Suitable Camelid V_(HH) that bind serum albumin include those disclosedin WO 2004/041862 (Ablynx N.V.) and in WO2007080392 (which V_(HH)sequences and their nucleic acid counterpart are incorporated herein byreference and form part of the disclosure of the present text), such asSequence A (SEQ ID NO:518), Sequence B (SEQ ID NO:519), Sequence C (SEQID NO:520), Sequence D (SEQ ID NO:521), Sequence E (SEQ ID NO:522),Sequence F (SEQ ID NO:523), Sequence G (SEQ ID NO:524), Sequence H (SEQID NO:525), Sequence I (SEQ ID NO:526), Sequence J (SEQ ID NO:527),Sequence K (SEQ ID NO:528), Sequence L (SEQ ID NO:529), Sequence M (SEQID NO:530), Sequence N (SEQ ID NO:531), Sequence O (SEQ ID NO:532),Sequence P (SEQ ID NO:533), Sequence Q (SEQ ID NO:534), these sequencenumbers corresponding to those cited in WO2007080392 or WO 2004/041862(Ablynx N.V.). In certain embodiments, the Camelid V_(HH) binds humanserum albumin and comprises an amino acid sequence that has at leastabout 80%, or at least about 85%, or at least about 90%, or at leastabout 95%, or at least about 96%, or at least about 97%, or at leastabout 98%, or at least about 99% amino acid sequence identity with ALB1disclosed in WO2007080392 or any one of SEQ ID NOS:518-534, thesesequence numbers corresponding to those cited in WO2007080392 or WO2004/041862.

In some embodiments, the ligand, agonist or antagonist comprises ananti-serum albumin dAb that competes with any anti-serum albumin dAbdisclosed herein for binding to serum albumin (e.g., human serumalbumin).

In an alternative embodiment, the agonist, antagonist or ligandcomprises a binding moiety specific for target antigen (eg, humanTNFR1), wherein the moiety comprises non-immunoglobulin sequences asdescribed in co-pending application PCT/GB2008/000453 filed 8 Feb. 2008,the disclosure of these binding moieties, their methods of productionand selection (eg, from diverse libraries) and their sequences areincorporated herein by reference as part of the disclosure of thepresent text)

Conjugation to a Half-Life Extending Moiety (Eg, Albumin)

In one embodiment, a (one or more) half-life extending moiety (eg,albumin, transferrin and fragments and analogues thereof) is conjugatedor associated with the target antigen-binding polypeptide, dAb, agonistor antagonist of the disclosure. Examples of suitable albumin, albuminfragments or albumin variants for use in a target antigen-binding formatare described in WO 2005077042, which disclosure is incorporated hereinby reference and forms part of the disclosure of the present text. Inparticular, the following albumin, albumin fragments or albumin variantscan be used in the present disclosure:

-   -   SEQ ID NO:1 (as disclosed in WO 2005077042, this sequence being        explicitly incorporated into the present disclosure by        reference);    -   Albumin fragment or variant comprising or consisting of amino        acids 1-387 of SEQ ID NO:1 in WO 2005077042;    -   Albumin, or fragment or variant thereof, comprising an amino        acid sequence selected from the group consisting of: (a) amino        acids 54 to 61 of SEQ ID NO:1 in WO 2005077042; (b) amino acids        76 to 89 of SEQ ID NO:1 in WO 2005077042; (c) amino acids 92 to        100 of SEQ ID NO:1 in WO 2005077042; (d) amino acids 170 to 176        of SEQ ID NO:1 in WO 2005077042; (e) amino acids 247 to 252 of        SEQ ID NO:1 in WO 2005077042; (f) amino acids 266 to 277 of SEQ        ID NO:1 in WO 2005077042; (g) amino acids 280 to 288 of SEQ ID        NO:1 in WO 2005077042; (h) amino acids 362 to 368 of SEQ ID NO:1        in WO 2005077042; (i) amino acids 439 to 447 of SEQ ID NO:1 in        WO 2005077042 (j) amino acids 462 to 475 of SEQ ID NO:1 in WO        2005077042; (k) amino acids 478 to 486 of SEQ ID NO:1 in WO        2005077042; and (1) amino acids 560 to 566 of SEQ ID NO:1 in WO        2005077042.

Further examples of suitable albumin, fragments and analogs for use in atarget antigen-binding format are described in WO 03076567, whichdisclosure is incorporated herein by reference and which forms part ofthe disclosure of the present text. In particular, the followingalbumin, fragments or variants can be used in the present disclosure:

-   -   Human serum albumin as described in WO 03076567, eg, in FIG. 3        (this sequence information being explicitly incorporated into        the present disclosure by reference);    -   Human serum albumin (HA) consisting of a single non-glycosylated        polypeptide chain of 585 amino acids with a formula molecular        weight of 66,500 (See, Meloun, et al., FEBS Letters 58:136        (1975); Behrens, et al., Fed. Proc. 34:591 (1975); Lawn, et al.,        Nucleic Acids Research 9:6102-6114 (1981); Minghetti, et al., J.        Biol. Chem. 261:6747 (1986));    -   A polymorphic variant or analog or fragment of albumin as        described in Weitkamp, et al., Ann. Hum. Genet. 37:219 (1973);    -   An albumin fragment or variant as described in EP 322094, eg,        HA(1-373, HA(1-388), HA(1-389), HA(1-369), and HA(1-419) and        fragments between 1-369 and 1-419;    -   An albumin fragment or variant as described in EP 399666, eg,        HA(1-177) and HA(1-200) and fragments between HA(1-X), where X        is any number from 178 to 199.

Where a (one or more) half-life extending moiety (eg, albumin,transferrin and fragments and analogues thereof) is used to format thetarget antigen-binding polypeptides, dAbs, agonists and antagonists ofthe disclosure, it can be conjugated using any suitable method, such as,by direct fusion to the target antigen-binding moiety (eg, anti-TNFR1dAb), for example by using a single nucleotide construct that encodes afusion protein, wherein the fusion protein is encoded as a singlepolypeptide chain with the half-life extending moiety located N- orC-terminally to the target antigen binding moiety. Alternatively,conjugation can be achieved by using a peptide linker between moeities,eg, a peptide linker as described in WO 03076567 or WO 2004003019 (theselinker disclosures being incorporated by reference in the presentdisclosure to provide examples for use in the present disclosure). Inone embodiment, conjugation can be through a helical linker such as thehelical linker as described herein. It will also be appreciated thatother linkers that may be useful for this purpose include those such asglycine-serine rich linkers. In one embodiment, the linker may be aprotease resistant linker. Typically, a polypeptide that enhances serumhalf-life in vivo is a polypeptide which occurs naturally in vivo andwhich resists degradation or removal by endogenous mechanisms whichremove unwanted material from the organism (e.g., human). For example, apolypeptide that enhances serum half-life in vivo can be selected fromproteins from the extracellular matrix, proteins found in blood,proteins found at the blood brain barrier or in neural tissue, proteinslocalized to the kidney, liver, lung, heart, skin or bone, stressproteins, disease-specific proteins, or proteins involved in Fctransport.

In embodiments of the disclosure described throughout this disclosure,instead of the use of an anti-target antigen “dAb” in an agonist,antagonist or ligand of the disclosure, it is contemplated that theskilled addressee can use a polypeptide or domain that comprises one ormore or all 3 of the CDRs of a dAb of the disclosure that binds targetantigen (e.g., CDRs grafted onto a suitable protein scaffold orskeleton, eg an affibody, an SpA scaffold, an LDL receptor class Adomain or an EGF domain) The disclosure as a whole is to be construedaccordingly to provide disclosure of agonists or antagonists using suchdomains in place of a dAb. In this respect, see WO2008096158, thedisclosure of which is incorporated by reference.

In one embodiment, therefore, an agonist or antagonist of the disclosurecomprises an immunoglobulin single variable domain or domain antibody(dAb) that has binding specificity for target antigen or thecomplementarity determining regions of such a dAb in a suitable format.The agonist or antagonist can be a polypeptide that consists of such adAb, or consists essentially of such a dAb. The agonist or antagonistcan be a polypeptide that comprises a dAb (or the CDRs of a dAb) in asuitable format, such as an antibody format (e.g., IgG-like format,scFv, Fab, Fab′, F(ab′)2), or a dual specific ligand that comprises adAb that binds target antigen and a second dAb that binds another targetprotein, antigen or epitope (e.g., serum albumin).

Polypeptides, dAbs, agonists and antagonists according to the disclosurecan be formatted as a variety of suitable antibody formats that areknown in the art, such as, IgG-like formats, chimeric antibodies,humanized antibodies, human antibodies, single chain antibodies,bispecific antibodies, antibody heavy chains, antibody light chains,homodimers and heterodimers of antibody heavy chains and/or lightchains, antigen-binding fragments of any of the foregoing (e.g., a Fvfragment (e.g., single chain Fv (scFv), a disulfide bonded Fv), a Fabfragment, a Fab′ fragment, a F(ab′)₂ fragment), a single variable domain(e.g., V_(H), V_(L)), a dAb, and modified versions of any of theforegoing (e.g., modified by the covalent attachment of polyalkyleneglycol (e.g., polyethylene glycol, polypropylene glycol, polybutyleneglycol) or other suitable polymer).

In some embodiments, the disclosure provides a ligand (eg, an anti-TNFR1antagonist) that is an IgG-like format. Such formats have theconventional four chain structure of an IgG molecule (2 heavy chains andtwo light chains), in which one or more of the variable regions (V_(H)and or V_(L)) have been replaced with a dAb of the disclosure. In oneembodiment, each of the variable regions (2 V_(H) regions and 2 V_(L)regions) is replaced with a dAb or single variable domain, at least oneof which is an anti-target antigen dAb according to the disclosure. ThedAb(s) or single variable domain(s) that are included in an IgG-likeformat can have the same specificity or different specificities. In someembodiments, the IgG-like format is tetravalent and can have one(anti-target antigen only), two (eg, anti-target antigen and anti-SA),three or four specificities. For example, the IgG-like format can bemonospecific and comprises 4 dAbs that have the same specificity;bispecific and comprises 3 dAbs that have the same specificity andanother dAb that has a different specificity; bispecific and comprisetwo dAbs that have the same specificity and two dAbs that have a commonbut different specificity; trispecific and comprises first and seconddAbs that have the same specificity, a third dAb with a differentspecificity and a fourth dAb with a different specificity from thefirst, second and third dAbs; or tetraspecific and comprise four dAbsthat each have a different specificity. Antigen-binding fragments ofIgG-like formats (e.g., Fab, F(ab′)2, Fab′, Fv, scFv) can be prepared.In one embodiment, the IgG-like formats or antigen-binding fragmentsthereof do not crosslink target antigen, for example, the format may bemonovalent for target antigen. If complement activation and/or antibodydependent cellular cytotoxicity (ADCC) function is desired, the ligandcan be an IgG1-like format. If desired, the IgG-like format can comprisea mutated constant region (variant IgG heavy chain constant region) tominimize binding to Fc receptors and/or ability to fix complement. (seee.g. Winter et al., GB 2,209,757 B; Morrison et al., WO 89/07142; Morganet al., WO 94/29351, Dec. 22, 1994).

The ligands of the disclosure (polypeptides, dAbs, agonists andantagonists) can be formatted as a fusion protein that contains a firstimmunoglobulin single variable domain that is fused directly to a secondimmunoglobulin single variable domain. If desired such a format canfurther comprise a half-life extending moiety. For example, the ligandcan comprise a first immunoglobulin single variable domain that is fuseddirectly to a second immunoglobulin single variable domain that is fuseddirectly to an immunoglobulin single variable domain that binds serumalbumin.

Generally the orientation of the polypeptide domains that have a bindingsite with binding specificity for a target, and whether the ligandcomprises a linker, is a matter of design choice. However, someorientations, with or without linkers, may provide better bindingcharacteristics than other orientations. All orientations (e.g.,dAb1-linker-dAb2; dAb2-linker-dAb 1) are encompassed by the disclosureare ligands that contain an orientation that provides desired bindingcharacteristics can be easily identified by screening.

Polypeptides and dAbs according to the disclosure, including dAbmonomers, dimers and trimers, can be linked to an antibody Fc region,comprising one or both of C_(H)2 and C_(H)3 domains, and optionally ahinge region. For example, vectors encoding ligands linked as a singlenucleotide sequence to an Fc region may be used to prepare suchpolypeptides. The disclosure moreover provides dimers, trimers andpolymers of the aforementioned dAb monomers.

EXEMPLIFICATION Example 1

Aim of the Study

The aim of the study was to obtain protease resistant variants of GLP-1ALBUDAB™ fusions by performing phage selection on a libraries derivedfrom a GLP-1 variant comprising DPP IV resistant GLP-1 (referred to asherein as *GLP-1) in combination with treatment of phage with variousproteases (including those naturally occurring in the expression host).As described herein, an ALBUDAB™ is an immunoglobulin single variabledomain that specifically binds serum albumin.

GLP-1 Receptor

The glucagon-like peptide-1 receptor (GLP-1R) belongs to the family B1of seven transmembrane G protein-coupled receptors. Binding interactionsbetween the receptor and its natural agonist ligand GLP-1 is initiatedby ligand binding to extracellular N-terminal domain of the receptor(ECD GLP-1R) and followed by interaction with the core of transmembraneportion (Al-Sabah et al, 2003; FEBS Lett; 553(3): 342-6). It has beenshown that GLP-1 binding to the isolated N-terminal domain is retainedif the transmembrane core is removed, although the affinity is reduced(Lopez de Maturana et al, 2003; J. Biol. Chem; 278(12): 10195-200).Since the use of the whole receptor is not desirable for phage selectionin solution, due to the poor solution solubility of receptors withtransmembrane domains in aqueous solution without solubilisingdetergents, the isolated extracellular domain was used for phage captureto simplify the experiment and enrich phages displaying molecules withaffinity to ECD GLP-1R.

The nucleotide and amino acid sequences for the His tagged Fc monomer ofECD GLP-1R are as follows:

Nucleotide sequence (SEQ ID NO: 1):ATGGCCGGCG CCCCCGGCCC GCTGCGCCTT GCGCTGCTGCTGCTCGGGAT GGTGGGCAGG GCCGGCCCCC GCCCCCAGGGTGCCACTGTG TCCCTCTGGG AGACGGTGCA GAAATGGCGAGAATACCGAC GCCAGTGCCA GCGCTCCCTG ACTGAGGATCCACCTCCTGC CACAGACTTG TTCTGCAACC GGACCTTCGATGAATACGCC TGCTGGCCAG ATGGGGAGCC AGGCTCGTTCGTGAATGTCA GCTGCCCCTG GTACCTGCCC TGGGCCAGCAGTGTGCCGCA GGGCCACGTG TACCGGTTCT GCACAGCTGAAGGCCTCTGG CTGCAGAAGG ACAACTCCAG CCTGCCCTGGAGGGACTTGT CGGAGTGCGA GGAGTCCAAG CGAGGGGAGAGAAGCTCCCC GGAGGAGCAG CTCCTGTTCC TCAAGCTTGAGCCCAAATCG GCCGACAAAA CTCACACATC ACCACCGTCACCAGCACCTG AACTCCTGGG GGGACCGTCA GTCTTCCTCTTCCCCCCAAA ACCCAAGGAC ACCCTCATGA TCTCCCGGACCCCTGAGGTC ACATGCGTGG TGGTGGACGT GAGCCACGAAGACCCTGAGG TCAAGTTCAA CTGGTACGTG GACGGCGTGGAGGTGCATAA TGCCAAGACA AAGCCGCGGG AGGAGCAGTACAACAGCACG TACCGGGTGG TCAGCGTCCT CACCGTCCTGCACCAGGACT GGCTGAATGG CAAGGAGTAC AAGTGCAAGGTCTCCAACAA AGCCCTCCCA GCCCCCATCG AGAAAACCATCTCCAAAGCC AAAGGGCAGC CCCGAGAACC ACAGGTGTACACCCTGCCCC CATCCCGGGA TGAGCTGACC AAGAACCAGGTCAGCCTGAC CTGCCTGGTC AAAGGCTTCT ATCCCAGCGACATCGCCGTG GAGTGGGAGA GCAATGGGCA GCCGGAGAACAACTACAAGA CCACGCCTCC CGTGCTGGAC TCCGACGGCTCCTTCTTCCT CTACAGCAAG CTCACCGTGG ACAAGAGCAGGTGGCAGCAG GGGAACGTCT TCTCATGCTC CGTGATGCATGAGGCTCTGC ACAACCACTA CACGCAGAAG AGCCTCTCCCTGTCTCCGGG TAAACATCAC CATCATCATC ACTGAAmino Acid sequence (SEQ ID NO: 2):MAGAPGPLRL ALLLLGMVGR AGPRPQGATV SLWETVQKWREYRRQCQRSL TEDPPPATDL FCNRTFDEYA CWPDGEPGSFVNVSCPWYLP WASSVPQGHV YRFCTAEGLW LQKDNSSLPWRDLSECEESK RGERSSPEEQ LLFLKLEPKS ADKTHTSPPSPAPELLGGPS VFLFPPKPKD TLMISRTPEV TCVVVDVSHEDPEVKFNWYV DGVEVHNAKT KPREEQYNST YRVVSVLTVLHQDWLNGKEY KCKVSNKALP APIEKTISKA KGQPREPQVYTLPPSRDELT KNQVSLTCLV KGFYPSDIAV EWESNGQPENNYKTTPPVLD SDGSFFLYSK LTVDKSRWQQ GNVFSCSVMH EALHNHYTQK SLSLSPGKHH HHHH

The GLP-1R ECD was also expressed with an IgG Fc tag, which enabledinitial purification of the protein on Protein A agarose. During phageselections, the soluble receptor could then be captured using Protein Acoated beads.

Test Phage Selections

Tests were performed to verify that the extracellular domain of GLP-1Receptor can be used for phage display library selections.

Phage Vector

A filamentous phage (fd) display vector, pDOM34 (which is a derivativeof pDOM4) was used, which is based on fd vector with a myc tag andwherein a protein sequence can be cloned in between restriction sites toprovide a protein-gene III fusion. (pDOM4, as described in WO2007/085815, is a derivative of the Fd phage vector in which the geneIII signal peptide sequence is replaced with the yeast glycolipidanchored surface protein (GAS) signal peptide (WO 2005/093074). It alsocontains a c-myc tag between the leader sequence and gene III, whichputs the gene III back in frame)

Modifications of pDOM4 which lead to pDOM34 include:

-   -   1.) Knock out of the NcoI site at 7476nt position of pDOM4    -   2.) Deletion of the Myc tag fused to N′terminus of cpIII    -   3.) Introduction of NcoI restriction site to facilitate cloning        straight after the signal peptide.

The genes encoding library repertoires were cloned as NcoI/NotIfragments.

The vector was propagated in E. coli MACH I™ cells, isolated with use ofa PLASMID MEGA PREP™ kit (Qiagen) and the supercoiled fraction wasisolated by cesium chloride gradient ultracentrifugation using standardtechniques (Sambrook and Maniatis 1989). Vector was cut with NcoI andNotI enzymes following by PstI to reduce self ligation rate. Followedphenol/chloroform extraction, DNA was ethanol precipitated and purifiedfrom the non required “stuffer” DNA fragment between the NcoI and NotIsites on CHROMASPIN™ TE-1000 columns (Clontech). After purificationvector DNA was used to test ligations with diversified DAT-X DNAfragments.

DAT-X Libraries Construction

Eighteen repertoires were constructed based on the DAT-X parentalmolecule comprising DPP IV resistant GLP-1, which will be further called*GLP-1.

*GLP-1 (7-37):

Amino acid sequence (SEQ ID NO: 3) HGEGTFTSDVSSYLEGQAAKEFIAWLVKGRGNucleotide sequence: (SEQ ID NO: 4)CATGGTGAAGGGACCTTTACCAGTGATGTAAGTTCTTATTTGGAAGGCCAAGCTGCCAAGGAATTCATTGCTTGGCTGGTGAAAGGCCGAGGA

The DAT-X parental molecules further comprises a fusion with DOM7h-14 (adomain antibody (dAb) which binds serum albumin (ALBUDAB™)).

DOM7h-14:

Amino acid sequence: (SEQ ID NO: 5)DIQMTQSPSSLSASVGDRVTITCRASQWIGSQLSWYQQKPGKAPKLLIMWRSSLQSGVPSRFSGSGSGTDFTLTISSLQPEDFATYYCAQGAALPRTFGQ GTKVEIKRNucleotide sequence: (SEQ ID NO: 6)GACATCCAGATGACCCAGTCTCCATCCTCCCTGTCTGCATCTGTAGGAGACCGTGTCACCATCACTTGCCGGGCAAGTCAGTGGATTGGGTCTCAGTTATCTTGGTACCAGCAGAAACCAGGGAAAGCCCCTAAGCTCCTGATCATGTGGCGTTCCTCGTTGCAAAGTGGGGTCCCATCACGTTTCAGTGGCAGTGGATCTGGGACAGATTTCACTCTCACCATCAGCAGTCTGCAACCTGAAGATTTTGCTACGTACTACTGTGCTCAGGGTGCGGCGTTGCCTAGGACGTTCGGCCAAGGGACCAAGGTGGAAATCAAACGG*GLP-1 and DOM7h-14 in DAT-X parental molecule are connected by helicallinker:Helical Linker

Amino acid sequence: (SEQ ID NO: 7)KEAAAKEAAAKEAAAKELAAKEAAAKEAAAKEAAAKELAA Nucleotide sequence:(SEQ ID NO: 8) AAAGAAGCGGCGGCGAAAGAAGCGGCGGCGAAAGAAGCGGCGGCGAAAGAATTGGCCGCAAAAGAAGCGGCGGCGAAAGAAGCGGCGGCGAAAGAAGCG GCGGCGAAAGAATTGGCCGCA

To cover the whole sequence of the *GLP-1 (excluding sites known to beimportant for receptor binding (as described, for example, in Sarraustede Menthière et al. Eur J Med Chem. 2004 June; 39(6):473-80; Neidigh etal. Biochemistry. 2001 Nov. 6; 40(44):13188-200; Hjorth et al. J BiolChem. 1994 Dec. 2; 269(48):30121-4 and Gallwitz et al. Regul Pept. 1996May 7; 63(1):17-22)), 17 repertoires were constructed using an assemblyPCR protocol using PHUSION™ high fidelity Polymerase (NEB) in a 50microliters reaction volume. Four randomized nucleotides per librarywere introduced by primers in primary PCRs and then assembly wasperformed with biotinylated primers. Error prone PCR using MUTAZYME™ kit(Stratagene), biotinylated primers and 5-50 pg of template for a 50 μlreaction introduced random mutations within *GLP-1. Due to the shortlength of the *GLP-1 nucleotide sequence, error prone PCR was performedtwice, to increase the mutation rate.

After digestion with NcoI and NotI, the inserts were purified fromundigested products with streptavidin-coated beads. Test ligation wasperformed where digested products were ligated into pDOM34 at thecorresponding sites.

Sequencing of the test ligation clones confirmed the expecteddiversification in all the libraries therefore the full scale ligationand transformation of the libraries followed. The ligation was performedin a total volume of 500 microliters, with 1 microgram of the digestedvector and insert in the ratio 1:2 with T4 DNA ligase (NEB). Eachlibrary was transformed in two shots, 10 microliters per 100 microlitersof electrocompetent E. coli TB1 cells and after recovery, 100 ml ofmedia for 1 h in 37° C. with agitation, libraries were plated on tolarge (22 cm) square plates containing 2×TY Tet agar. Plates were grownovernight and then scraped into 5 mls of 2×TY with 15% glycerol forstocks preparation. Libraries sizes were in the in range of 10⁷-10⁸transformants.

For phage library preparation a library culture was started byinoculation of 100 microliters of glycerol stock into 200 milliliters of2×TY media containing antibiotic such that the final density of theculture immediately following inoculation did not exceed OD₆₀₀=0.1. Thelibraries were cultured overnight for about 18 hours at 37° C. withagitation. Culture was pelleted by centrifugation and phage librarieswere prepared by double precipitation with PEG and resuspended in PBS.

Several clones from unselected libraries were randomly chosen forsequencing to confirm successful libraries construction and the firstround of panning followed after phage library preparation.

The methods of panning, glycerol stock preparation and phageamplification are as it is described below unless otherwise noted.

The extracellular domain of GLP-1 receptor was used for panning. 100microliters of the phage libraries was incubated with 2% MARVELL™ PBScontaining 100 nM GLP-1R. The incubation was carried out for 1 h at RTand then the phages were combined with pre-blocked (2% MARVELL™ PBS, 1h, RT) protein A DYNABEADS™ (Dynal). After one hour incubation on arotating wheel at RT the beads were washed in the KINGFISHER™purification system (Thermo Electron Corporation) eight times with 0.1%Tween PBS (the KINGFISHER™ robot automates the washing process by usinga magnetic probe to transfer the beads from wash solution to washsolution) and the specific phages were recovered by elution in 500microliters of 0.1M Glycine pH 2.0. After neutralization with 100microliters of 1M Tris-Cl pH 8.0 phage was used for infection of logphase E. coli TG1 cells for 45 min at 37° C. Infected cells were platedon agar Tet plates which were grown overnight at 37° C. The titers oflibraries, input output and library size are presented in the tablebelow.

1^(st) selection; phage φ/ml Library Library size Input output  1 2.8 ×10⁸ 3.9 × 10¹⁰ 3.2 × 10⁷  2 1.2 × 10⁸ 1.0 × 10¹¹ 1.0 × 10⁶  3 2.4 × 10⁷4.6 × 10¹⁰ 7.0 × 10⁵  4 8.0 × 10⁷ 1.0 × 10¹¹ 8.0 × 10⁶  5 4.0 × 10⁷ 2.6× 10⁹ 1.0 × 10⁷  6 8.0 × 10⁷ 7.3 × 10¹⁰ 6.0 × 10⁶  7   4 × 10⁷ 8.0 × 10⁹6.0 × 10⁶  8 2.8 × 10⁷ 5.4 × 10⁹ 1.0 × 10⁷  9 6.8 × 10⁷ 9.4 × 10⁹ 5.0 ×10⁶ 10 2.0 × 10⁸ 5.7 × 10⁸ 1.5 × 10⁶ 11 8.8 × 10⁸ 4.5 × 10⁹ 2.0 × 10⁶ 126.6 × 10⁸ 4.0 × 10⁹ 1.6 × 10⁶ 13 1.8 × 10⁸ 6.7 × 10¹⁰ 2.0 × 10⁵ 14 4.8 ×10⁷ 6.0 × 10⁹ 3.0 × 10⁵ 15 6.0 × 10⁷ 4.2 × 10¹⁰ 1.0 × 10⁶ 16 2.4 × 10⁸1.6 × 10¹⁰ 4.8 × 10⁵ 17 4.2 × 10⁸ 1.3 × 10¹⁰ 1.4 × 10⁶ 18 Error prone1.5 × 10⁸ 2.5 × 10⁹ 6.0 × 10⁵ Self ligation 4.0 × 10⁵ DAT-X control —4.0 × 10⁹ 1.8 × 10⁷

The first selection round produced a reasonable output for alllibraries.

Glycerol stocks were prepared by scraping the colonies from agar plateswith 2 mls of 2×TY media containing 15% glycerol and aliquotted intocryogenic vials.

The following selections were performed on the pooled phage. Theamplified phage was obtained by combined culture of the E. coliglycerols containing outputs from the 1^(st) selection from all 18libraries. The culture was started by inoculation of 50 microliters ofeach panned library glycerol stock in 1 liter of 2×TY media withantibiotic. The culture was divided into two 2 L shaker flasks, halfliter into each and cultured overnight in 37° C. with agitation 250 rpm.The phage was prepared after 18-20h of culture by single precipitationwith PEG and resuspension in PBS.

DAT-X Phage Display Libraries Selection with Protease

Amplified phage from 1^(st) selection output was used for the furtherselections with constant concentration of GLP-1R, 100 nM. Additionally,before selection with trypsin, a batch of phage from the 1^(st)selection output was subcloned with the R108W mutation in the ALBUDAB™sequence. This mutation renders the Vkappa ALBUDAB™ clone more resistantfor trypsin treatment when displayed on phage. This is because thearginine residue at the carboxy terminus of the dAb that links thedomain antibody to the pIII protein is trypsin sensitive. Mutation atthis site removes the trypsin cleavage site, and improves the targetingof protease selections to the desired region of the target peptide.Thus, two batches of phage, with or without the R108W mutation in theALBUDAB™, were used ready in the second selection round.

Phage was treated with the proteases trypsin or chymostrypsin atdifferent concentrations or left untreated before incubation withreceptor for 1 h at room temperature. The 2^(nd) selection titers (φ/ml)are presented in the table below.

No Φ Protease input protease 1 μg/ml 10 μg/ml DAT-X c+ α-chymotrypsin 2× 10¹⁰ 7 × 10⁶ 4 × 10⁵ <1 × 10⁴ R108W c+ Trypsin 2 × 10¹⁰ 6 × 10⁷ 3 ×10⁶  4 × 10⁴ Lib 1-18 α-chymotrypsin 2 × 10¹¹ 3 × 10⁸ 2 × 10⁶  3 × 10⁴R108W Trypsin 1 × 10¹² 1 × 10⁸ 1 × 10⁷  3 × 10⁶

Phage outputs from each selection (0 μg/ml-10 μg/ml) was amplified byinoculation of 50 microliters of glycerol stock into 50 milliliters of2×TY with Tet and overnight culture, 20h at 37° C. with agitation.Purified phage was used for the 3^(rd) selection round, with the sameincubation conditions.

The 3^(rd) selection titers (φ/ml) are presented in the tables below.

Φ out α-chymotrypsin 2^(nd) with concentration: input No protease 1μg/ml 10 μg/ml Lib 1-18_No protease 1 × 10¹⁰ 7 × 10⁸ 5 × 10⁴ ~1 × 10²Lib 1-18_1 μg/ml 1 × 10¹⁰ 8 × 10⁷ 5 × 10⁴ ~1 × 10³ Lib 1-18_10 μg/ml 1 ×10¹⁰ 2 × 10⁸ 1 × 10⁶   1 × 10⁴ Control DAT-X 1 × 10¹⁰ 5 × 10⁶ 6 × 10⁴ ND

Φ out Trypsin 2^(nd) with concentration: input No protease 1 μg/ml 10μg/ml Lib 1-18 R108W_No 2 × 10¹¹ 2 × 10⁹ 1 × 10⁷ 1 × 10⁶ protease Lib1-18 1 × 10¹¹ 5 × 10⁸ 1 × 10⁷ 2 × 10⁵ R108W_1 μg/ml Lib 1-18 1 × 10¹¹ 7× 10⁷ 1 × 10⁷ 1 × 10⁶ R108W_10 μg/ml Control DAT-X R108W 3 × 10¹⁰ 1 ×10⁷ 1 × 10⁷ 3 × 10⁴

Because the diversity of clones has already decreased after the 3^(rd)round, as verified by colony sequencing of a representative set ofclones, a few clones from selection outputs were expressed as solubleproteins as detailed below.

DAT-X Phage Display Libraries Selection Outputs

Several *GLP-1 variants were chosen to be cloned as a fusion withALBUDAB™ but with alternative linkers as described below, expressed,purified and assayed in the GLP-1 receptor assay. Their amino acidsequences are set out as sequences 1-10 (see FIG. 1). One *GLP-1sequence variant (7) was abundantly present in outputs from selectionswith both chymotrypsin and trypsin treatment and as a fusion is calledDMS7149, two were present in outputs when chymotrypsin was used (DMS7150(8) and 51(9)), one was observed in the outputs where only naturalproteases were acting in the cells during the phage expression andsecretion and no pretreatment with trypsin or chymotrypsin was used(DMS7148 (6)) and one cloned to create a knock out of trypsin cleavagesites (DMS7152 (10)).

Proteins with the amino acid sequences 1-4 (see FIG. 1) were assayed andshowed low potency relative to GLP-1 and control DAT-X variant. Edmansequencing suggested that the proteins were wrongly processed.

Cloning was performed by introducing mutations into DAT-Y clone whichcomprises *GLP-1 linked to DOM7h-14 by an alternative linker having theamino acid sequence: PSS (SEQ ID NO: 9) and nucleotide sequence:CCAAGCTCG (SEQ ID NO: 10).

Chosen mutations were introduced to the *GLP-1 sequence by primers inprimary PCR and in the assembly PCR the NcoI and BamHI digestion siteswere introduced on 5′ and 3′ terminus respectively of the fusionsequence.

Assembly PCR was digested with NcoI and BamHI restriction endonucleases.

Expression vector pDOM35 was prepared for cloning.

Vector pDOM35 is a derivative of pET12a with modifications:

-   -   The last three residues of OmpT signal peptide are changed from        SFA to AWA which improves processing at the correct site by the        signal peptidase of E. coli.    -   The NcoI site was introduced to facilitate cloning straight        after the signal peptide.    -   A ‘stuffer’ is present between NcoI and BamHI site

pDOM35 was digested with NcoI and BamHI and cut assembly PCRs wereligated into the vector with use of QUICK LIGATION KIT™ (NEB). 2microliters of ligation was used for transformation of MACH I™ cells andafter recovery cells were plated on agar plates containing carbenicilinand grown overnight. Colonies were sequenced and these containingcorrect sequence were used for plasmid propagation and its isolation(PLASMID MINI PREP™ kit, Qiagen). BL21 (DE3) cells were transformed withplasmid DNA and resulting colonies were used for inoculation ofexpression culture.

Expression was performed by inoculation of a 50 milliliter culture of2×TY media supplemented with OVERNIGHT EXPRESS™ autoinduction solutions(1 milliliter of Solution 1 (Cat. No. 71298), 2.5 milliliters ofSolution 2 (Cat. No. 71299), 50 microliters of Solution 3 (Cat. No71304), Novagen) and 100 microgram per milliliter of carbenicillin.Culture was carried overnight at 37° C., and then the culturesupernatant was clarified by centrifugation at 3700×g for 45 minutes.The expressed protein was then purified from the clarified supernatantusing PROTEIN L STREAMLINE™ (GE Healthcare, Cat. No. 28-4058-03, proteinL coupled), and eluted from the Protein L using 0.1M glycine pH 2.0,then neutralized using 0.2 volumes of 1M Tris pH 8.0.

The *GLP-1 variant portion from DMS7148 was also cloned as fusionDMS7161 (Sequence 11) with ALBUDAB™ of higher affinity, DOM7h-14-10, andconnected by the alternative, PSS linker, into the pDOM35 as it wasdescribed earlier.

DOM7h-14-10

Amino Acid sequence (SEQ ID NO: 22):DIQMTQSPSSLSASVGDRVTITCRASQWIGSQLSWYQQKPGKAPKLLIMWRSSLQSGVPSRFSGSGSGTDFTLTISSLQPEDFATYYCAQGLRHPKTFGQ GTKVEIKRNucleotide sequence (SEQ ID NO: 23):GACATCCAGATGACCCAGTCTCCATCCTCCCTGTCTGCATCTGTAGGAGACCGTGTCACCATCACTTGCCGGGCAAGTCAGTGGATTGGGTCTCAGTTATCTTGGTACCAGCAGAAACCAGGGAAAGCCCCTAAGCTCCTGATCATGTGGCGTTCCTCGTTGCAAAGTGGGGTCCCATCACGTTTCAGTGGCAGTGGATCTGGGACAGATTTCACTCTCACCATCAGCAGTCTGCAACCTGAAGATTTTGCTACGTACTACTGTGCTCAGGGTTTGAGGCATCCTAAGACGTTCGGCCAAGGGACCAAGGTGGAAATCAAACGG

After the plasmid DNA pDOM35 comprising sequence of DMS7161 wastransformed into BL21(DE3), glycerol stock was prepared from growncolonies, by scraping colonies into minimal media with glucose andaddition of glycerol, final conentration of approximately 15%.Expression of DMS7161 was started by inoculation of the glycerol into 50milliliters of minimal media (DMS7161 A) supplemented in Yeast Extractfor final concentration 10 g/liter (DMS7161 B) so as to obtain thestarting culture density of OD600=0.024. The culture was grown to OD600of approximately 1.4 at 30° C., then induced by the addition of 0.1 mMisopropyl-beta-d-thiogalactoside. Culture was continued for a further24h at 23° C. and then the culture supernatant was clarified bycentrifugation at 3700×g for 45 minutes. The expressed protein was thenpurified from the clarified supernatant using protein L, and eluted fromthe Protein L (GE Healthcare, Cat. No. 28-4058-03, protein L coupled)using 0.1M glycine pH2.0, then neutralized using 0.2 volumes of 1M TrispH8.0.

Quality Control of DMS7148-52

Proteins DMS7148-52 were expressed and visualized on non reducingSDS-PAGE, DMS7148 and DMS7161 clones were well expressed in E. coli withthe majority of material migrating at the expected size (FIGS. 2, 3 and4). Mass Spectrometry (FIG. 5 a)) and Edman sequencing analysesconfirmed the integrity of the sequence. All the other proteins weredegraded at the amino and carboxyl site of 25-Tryptophan (products24-142 and 26-142 respectively) where DMS7148 contains W25-D mutationand aspartic acid did not create a cleavage site for the naturalprotease acting in E. coli cells (FIG. 5 a) to f)). The degradationproduct 28-142 was also observed in the remaining clones.

Protein DMS7148 was assayed for activity in a GLP-1 receptor bindingassay according to the following protocol:

Background: GLP-1R is a 7TM G-protein coupled receptor which isexpressed on CHO cells. Activation of the receptor by GLP-1 or suchanalogues, leads to the conversion of ATP to cAMP by adenylate cyclasewhich is coupled to the receptor. CHO cells are stably transfected withthe 6CRE/luc reporter gene. On production of cAMP following GLP-1activation of the receptor, the promoter gene (containing 6 copies ofcAMP response element—6CRE) drives the expression of the luciferasereporter gene. This then catalyses a reaction with luciferin to producelight which can be measured on a luminometer.

Protocol: CHO 6CRE GLP1R cells (CHO K1 cells stably transfected with 6cAMP response element driving a luciferase reporter gene and also withhuman GLP-1 receptor) were seeded at 2×10⁵ cells/mL in suspension media.Suspension culture was maintained for forty-eight hours. Cells were thendiluted into 15 mM HEPES, 2 mM L glutamine (2.5×10⁵ cells/ml) anddispensed into 384-well plates containing 10 ul/well of the compound tobe assayed. After the addition of assay controls, plates were returnedto the incubator for 3h at 37° C. and 5% CO₂. After the incubation,STEADY GLO™ luciferase substrate (Promega) was added to the wells asdescribed in the kit and the plates sealed with self-adhesive plateseals (Weber Marking Systems Inc. Cat. No. 607780). Plates were placedin the reader (Packard TopCount) and pre-incubated for 5 minutes priorto reading fluorescence and plotting of results. Compound was assayed ata range of concentrations response curve to be fitted from which pC50swere calculated.

Protein DMS7148 was found to be active, however less active than GLP-1peptide (FIG. 6 and summarized below).

Molecule pEC50 % max response DMS 7148 9.45 107 GLP 7-36 11.92 97

DMS7161 was assayed for activity in a GLP-1 assay according to thefollowing protocol:

Method:

CHO 6CRE GLP1R cells were rapidly defrosted by half immersing thevial(s) in a 37° C. water bath, and the contents of the vial(s)transferred to a 50 ml falcon tube and 10 ml RPMI (phenol red free)assay media (Sigma, cat # R7509)+2 mM L-glutamine (Gibco, cat #25030)+15mM HEPES (Sigma, cat # H0887) added per vial. After counting andcentrifugation at 1200 rpm for 5 minutes cells were resuspended in theappropriate volume of RPMI assay media to give 1×10⁶ cells per ml and 50μl dispensed into each well of a white 96 well flat bottom tissueculture plate (COSTAR™ 96 well tissue culture plate, white sterile, cat#3917). Cells were incubated overnight at 37 C/5% CO₂. Next day cellwere removed from incubator and 50 μl of previously preparedcontrol/sample was added to wells and plate was returned to incubatorfor 3 hours 37° C. and 5% CO₂.

Preparing GLP-1(7-36) Control (Sigma, Cat # G814)

In a V-bottom 96 well plate add 41 of 1 mg/ml GLP-1(7-36) to 18 μl RPMIassay media to give a 30 μM solution. Add 2 μl of the 30 μM solution to298 μl RPMI assay media to give a 200 nM solution (for a finalconcentration in the assay of 100 nM). Serial dilute the control 1:10down the plate (15 μl control+135 μl RPMI assay media) to generate an 8point curve.

Preparing Exendin-4 Control (Sigma, Cat # E7144)

In a V-bottom 96 well plate add 2 μl of 1 mg/ml) Exendin-4 to 198 μlRPMI assay media to give a 2.39 μM solution. Add 2 μl of the 2.39 μMsolution to 237 μl RPMI assay media to give a 20 nM solution (for afinal concentration in the assay of 10 nM). Serial dilute the control1:10 down the plate (15 μl control+135 μl RPMI assay media) to generatean 8 point curve.

Preparing Unknown Samples

Use the same guidelines for preparation of the controls for thepreparation of the unknown samples. Make the top concentration at twicethe final assay concentration required and dilute 1:10 down the plate.

Preparing the Luciferase (Promega, Cat # E2620)

Remove the required number of BRIGHT-GLO™ luciferase aliquots from thefreezer and allow defrosting at RT in the dark. One 5 ml vial issufficient for one assay plate

After the incubation time 50 μl of BRIGHT-GLO™ luciferase reagent wasadded to all wells and the plate was incubated at room temperature for 3mins to allow cell lysis to occur. The luminescence (counts per second)was read using the MSE™ microplate reader, reading each well for 0.1sec. CPS of the background wells containing cells only, was subtractedfrom all other wells. The control wells (GLP-1(7-36) or Exendin-4)should exhibit maximum stimulation at the highest concentrations.Concentration effect curves of the unknown samples are fitted from whichthe EC50 is calculated with use of GRAPHPAD PRISM™ or EXCELFIT™software.

DMS7161 is potent with EC50 between 1.6 and 3.4 nM as shown in FIG. 7and summarized below.

EC50 (M) pEC50 ex-4 3.6E−09 8.45 DMS7161 A 3.4E−09 8.47 DMS7161 B1.6E−09 8.79DMS7161 was found to be as active as DMS7148

SUMMARY

Phage selection of diversified peptide fusion which was naturally verysensitive to proteases and degrades during expression in E. coli allowedus to identify the *GLP-1 variant-fusion which is resistant to naturalbacterial proteases and the same is expressible in E. coli. The proteasesites which were knocked out in this clone are similar to theserecognized by trypsin and chymotrypsin, however this sequence was notpresent in outputs from selections with additional trypsin orchymotrypsin treatment.

Sequence SEQ ID NO: His tagged Fc monomer of ECD GLP1R 1 Nucleotidesequence His tagged Fc monomer of ECD GLP1R 2 Amino acid sequence *GLP1(737) Amino acid sequence 3 *GLP1 (737) Nucleotide sequence 4 DOM7h14Amino acid sequence: 5 DOM7h14 Nucleotide sequence: 6 Helical linkerAmino acid sequence: 7 Helical linker Nucleotide sequence: 8 PSS 9 PSSnucleotide sequence: 10 DMS7190 11 DMS7191 12 DMS7192 13 DMS7193 14DMS7194 15 DMS7148 16 DMS7149 17 DMS7150 18 DMS7151 19 DMS7152 20DMS7161 21 DOM7h1410 Amino Acid sequence 22 DOM7h1410 Nucleotidesequence 23

What we claim is:
 1. An immunoglobulin single variable domain comprisinga CDR1 amino acid sequence as shown at residues 24 to 34 of SEQ ID NO:22; a CDR2 amino acid sequence as shown at residues 50 to 56 of SEQ IDNO: 22; and a CDR3 amino acid sequence as shown at residues 89 to 97 ofSEQ ID NO: 22.